### Example: Object Visualization Setup

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Demonstrates initializing the viewer, creating a box, and applying display and appearance settings.

```php
vinit
box b 10 10 10
vdisplay b
vfit

vsetdispmode b 1
vaspects -setColor red -setTransparency 0.2
vrotate 10 10 10
```

--------------------------------

### Plug-in Configuration Example in Resource File

Source: https://github.com/open-cascade-sas/occt/wiki/foundation_classes

An example entry from a plug-in resource file, showing how to define a plug-in's metadata. It includes a GUID and its corresponding library location. This format is used by the `Load()` method to find and load plug-ins.

```plaintext
! METADATADRIVER whose value must be OS or DM.

! FW
a148e300-5740-11d1-a904-080036aaa103.Location: libFWOSPlugin.so
```

--------------------------------

### Example: Split Operation Setup

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Sets up objects and tools for a Split operation by clearing previous arguments, adding shapes, and performing the initial intersection. The actual split is built using 'bsplit' (not shown in this snippet).

```php
box b1 10 10 10
box b2 5 5 5 10 10 10
box b3 -5 -5 -5 10 10 10

# Clear objects and tools from previous runs
bclearobjects
bcleartools
# add b1 as object
baddobjects b1
# add b2 and b3 as tools
baddtools b2 b3
# perform intersection
bfillds
```

--------------------------------

### Example: Preparing for Split Operation

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Shows the setup for a split operation: clearing previous arguments, adding shapes as objects and tools, and performing the intersection step with 'bfillds'. The actual split result is built with 'bsplit'.

```Tcl
box b1 10 10 10
box b2 5 5 5 10 10 10
box b3 -5 -5 -5 10 10 10

# Clear objects and tools from previous runs
bclearobjects
bcleartools
# add b1 as object
baddobjects b1
# add b2 and b3 as tools
baddtools b2 b3
# perform intersection
bfillds
```

--------------------------------

### DRAW Example: Initial Geometry Setup

Source: https://github.com/open-cascade-sas/occt/wiki/boolean_operations

Sets up initial geometric shapes (cylinder, sphere, plane) using DRAW commands. This is a prerequisite for demonstrating various boolean operations with the Cells Builder.

```php
pcylinder c 10 30 
psphere s 15
ttranslate s 0 0 30
plane p 0 0 20 1 0 0
mkface f p -25 30 -17 17
```

--------------------------------

### Build and Install FreeImage

Source: https://github.com/open-cascade-sas/occt/wiki/building_3rdparty

Commands to navigate to the source directory, build, and install FreeImage.

```bash
cd FREEIMAGE_SRC_DIR
```

```bash
make
```

```bash
make install
```

--------------------------------

### Install OCCT with MinGW Makefiles

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/build/build_occt/building_occt.md

Execute this command with mingw32-make to install the built libraries to the specified install folder.

```bash
mingw32-make install
```

--------------------------------

### Quick Start Build with vcpkg

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/build/build_occt/building_occt.md

This command configures and builds OCCT using vcpkg for dependency management. It enables several common third-party libraries and sets the build type to Release. Use this for a fast, automated setup.

```bash
cmake -S . -B build \
      -DBUILD_USE_VCPKG=ON \
      -DUSE_TBB=ON -DUSE_VTK=ON -DUSE_FREEIMAGE=ON \
      -DUSE_RAPIDJSON=ON -DUSE_DRACO=ON \
      -DCMAKE_BUILD_TYPE=Release
cmake --build build --config Release --parallel
```

--------------------------------

### Install OCCT with Make (Linux/macOS)

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/build/build_occt/building_occt.md

Execute this command with make to install the built libraries to the specified install folder.

```bash
make install
```

--------------------------------

### OCAF Plugin File Example

Source: https://github.com/open-cascade-sas/occt/wiki/sample_ocaf

Lists the required plug-ins for an OCAF application, specifying their GUIDs, locations, and the libraries they are found in. This includes base document drivers and custom application drivers.

```text
a148e300-5740-11d1-a904-080036aaa103.Location: FWOSPlugin
! base document drivers plugin
ad696000-5b34-11d1-b5ba-00a0c9064368.Location: PAppStdPlugin
ad696001-5b34-11d1-b5ba-00a0c9064368.Location: PAppStdPlugin
ad696002-5b34-11d1-b5ba-00a0c9064368.Location: PAppStdPlugin
47b0b826-d931-11d1-b5da-00a0c9064368.Location: PAppStdPlugin
47b0b827-d931-11d1-b5da-00a0c9064368.Location: PAppStdPlugin
```

--------------------------------

### Install Resource Files

Source: https://github.com/open-cascade-sas/occt/blob/master/CMakeLists.txt

Installs resource files from the 'resources' directory to the installation destination, preserving subdirectory structure.

```cmake
FILE_TO_LIST ("adm/RESOURCES" RESOURCES)
foreach(RESOURCE ${RESOURCES})
  get_filename_component(RESOURCE_FOLDER ${RESOURCE} DIRECTORY)
  if(NOT "${RESOURCE_FOLDER}" STREQUAL "")
    get_filename_component(RESOURCE_FOLDER ${RESOURCE_FOLDER} NAME)
    OCCT_INSTALL_FILE_OR_DIR ("resources/${RESOURCE}" "${INSTALL_DIR_RESOURCE}/${RESOURCE_FOLDER}")
  else()
    OCCT_INSTALL_FILE_OR_DIR ("resources/${RESOURCE}" "${INSTALL_DIR_RESOURCE}")
  endif()
endforeach()
```

--------------------------------

### Example Grids List

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/contribution/tests/tests.md

An example of a 'grids.list' file, showing two test grids: 'basic' and 'advanced'.

```plaintext
    001 basic
    002 advanced
```

--------------------------------

### Build and Install Tcl on macOS

Source: https://github.com/open-cascade-sas/occt/wiki/building_3rdparty

Configure, build, and install Tcl from source on macOS.

```bash
cd TCL_SRC_DIR/macosx
```

```bash
configure --enable-gcc  --enable-shared --enable-threads --prefix=TCL_INSTALL_DIR
```

```bash
make
```

```bash
make install
```

--------------------------------

### Get Help on Commands Starting with 'a'

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Demonstrates how to use the 'help' command to get information on all commands starting with the letter 'a'.

```tcl
# Gives help on all commands starting with *a*

```

--------------------------------

### vpointcloud Command Example

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Shows how to create a point cloud with specified parameters using the vpointcloud command.

```php
vinit
vpointcloud pc 0 0 0 100 100000 surface -randColor
vfit
```

--------------------------------

### Example GUID

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/ocaf/ocaf.md

A Global Universal ID (GUID) is a string of 37 characters intended to uniquely identify an object.

```text
2a96b602-ec8b-11d0-bee7-080009dc3333
```

--------------------------------

### Example: Translation Ratio on IGES Faces

Source: https://github.com/open-cascade-sas/occt/wiki/iges

An example demonstrating how to use 'tpstat' to get the translation ratio specifically for IGES faces.

```draw
Draw:> tpstat *l iges-faces
```

--------------------------------

### vpoint Command Example

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Demonstrates creating a point in 3D space using the vpoint command.

```php
vinit
vpoint p 0 0 0
```

--------------------------------

### Example: Shading and Sub-object Display

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Examples showing how to apply shading to a sphere and display sub-objects.

```php
vinit 
psphere s 20 
vdisplay s 
vfit 
vsetdispmode 1 
vsetshading s 0.005
```

```php
vinit 
box b 10 10 10 
psphere s 20 
vdisplay b s 
vfit 
vsetdispmode 1 
vsub b 1
```

--------------------------------

### GetUAttribute: Get a User Attribute

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Finds a UAttribute attribute at the specified entry using a local GUID. Requires the GUID to be set in a variable.

```php
GetUAttribute dfname entry loacalGUID 
```

```php
set localGUID "c73bd076-22ee-11d2-acde-080009dc4422" 
GetUAttribute D 0:2 ${localGUID} 
```

--------------------------------

### Setting up a 3D View and Lights

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/visualization/visualization.md

This snippet demonstrates how to create and configure a 3D view, including setting up lighting and associating it with a window. It covers creating aspect fill areas, adding primitives, and managing lights.

```cpp
occ::handle<Graphic3d_AspectFillArea3d> anAspects = new Graphic3d_AspectFillArea3d (Aspect_IS_SOLID, Quantity_NOC_RED,
                                                                               Quantity_NOC_RED, Aspect_TOL_SOLID, 1.0f,
                                                                               Graphic3d_NameOfMaterial_Gold, Graphic3d_NameOfMaterial_Gold);
aPrsGroup->SetGroupPrimitivesAspect (anAspects);
aPrsGroup->AddPrimitiveArray (aTriangles);

// Create Ambient and Infinite Lights in this Viewer
occ::handle<V3d_AmbientLight>     aLight1 = new V3d_AmbientLight (Quantity_NOC_GRAY50);
occ::handle<V3d_DirectionalLight> aLight2 = new V3d_DirectionalLight (V3d_Zneg, Quantity_NOC_WHITE, true);
aViewer->AddLight (aLight1);
aViewer->AddLight (aLight2);
aViewer->SetLightOn();

// Create a 3D quality Window with the same DisplayConnection
// @note Xw_Window is X11-only. Cross-platform code should use Aspect_Window or the AIS context instead.
occ::handle<Xw_Window> aWindow = new Xw_Window (aDispConnection, "Test V3d", 100, 100, 500, 500);
aWindow->Map(); // Map this Window to this screen

// Create a Perspective  View in this Viewer
occ::handle<V3d_View> aView = new V3d_View (aViewer);
aView->Camera()->SetProjectionType (Graphic3d_Camera::Projection_Perspective);
// Associate this View with the Window
aView->SetWindow (aWindow);
// Display presentation in this View
aStruct->Display();
// Finally update the Visualization in this View
aView->Update();
// Fit view to object size
aView->FitAll();
```

--------------------------------

### Create and Get GUID of an Integer Attribute

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/ocaf/ocaf.md

Create a new integer attribute and retrieve its unique GUID using the ID() method inherited from TDF_Attribute.

```cpp
occ::handle<TDataStd_Integer> INT = new TData_Integer();
Standard_GUID guid = INT->ID();
```

--------------------------------

### OCAF Resource File Example

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/samples/ocaf.md

This is an example of a resource file that declares a new model document OCAF-MyApplication. It maps document types to storage and retrieval drivers using GUIDs.

```text
formatlist:OCAF-MyApplication
OCAF-MyApplication.Description: MyApplication Document Version 1.0
OCAF-MyApplication.FileExtension: sta
OCAF-MyApplication.StoragePlugin: ad696000-5b34-11d1-b5ba-00a0c9064368
OCAF-MyApplication.RetrievalPlugin: ad696001-5b34-11d1-b5ba-00a0c9064368
OCAF-MyApplicationSchema: ad696002-5b34-11d1-b5ba-00a0c9064368
OCAF-MyApplication.AttributeStoragePlugin: 47b0b826-d931-11d1-b5da-00a0c9064368
OCAF-MyApplication.AttributeRetrievalPlugin: 47b0b827-d931-11d1-b5da-00a0c9064368
```

--------------------------------

### Class Method Naming Convention

Source: https://github.com/open-cascade-sas/occt/wiki/coding_rules

Public methods should start with an uppercase letter, while protected and private methods should start with a lowercase letter. This example shows a getter and setter for an integer value.

```cpp
class MyPackage_MyClass
{

public:

  Standard_Integer Value() const;
  void             SetValue (const Standard_Integer theValue);

private:

  void setIntegerValue (const Standard_Integer theValue);

};
```

--------------------------------

### Create and Display Instance using vconnectto

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/visualization/visualization.md

Demonstrates creating an instance of an object and displaying it at a specified location using TCL commands.

```tcl
pload MODELING VISUALIZATION
vinit
psphere s 1
vdisplay s
vconnectto s2 3 0 0 s  # make instance
vfit
```

--------------------------------

### Get Nearest Solution Point (3D)

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/modeling_algos/modeling_algos.md

Retrieves the solution point that is closest to the original starting point.

```cpp
gp_Pnt P1 = Projector.NearestPoint();
```

--------------------------------

### Get Shape Volume

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Retrieves the volume of a specified shape or label within a document. No output is shown in the example.

```tcl
XGetVolume D 0:1:1:1
```

--------------------------------

### Build and Install VTK

Source: https://github.com/open-cascade-sas/occt/wiki/building_3rdparty

Use ccmake to configure and build the VTK library.

```bash
ccmake VTK_SRC_DIR
```

```bash
make
```

```bash
make install
```

--------------------------------

### Get Shape Centroid

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Retrieves the center of gravity coordinates for a given shape or label in a document. No output is shown in the example.

```tcl
XGetCentroid D 0:1:1:1
```

--------------------------------

### Erase Objects by Name Pattern

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Removes objects from all views. This example erases objects whose names start with 'c_'.

```Tcl
# erase everything with a name starting with c_ 
foreach var [directory c_*] {erase $var}
```

--------------------------------

### Setup Documentation Targets

Source: https://github.com/open-cascade-sas/occt/blob/master/CMakeLists.txt

Sets up documentation targets if BUILD_DOC_Overview or BUILD_DOC_RefMan options are enabled. It includes the necessary CMake file for documentation.

```cmake
if (BUILD_DOC_Overview OR BUILD_DOC_RefMan)
  OCCT_INCLUDE_CMAKE_FILE ("adm/cmake/occt_doc")
  # Setup documentation targets
  OCCT_SETUP_DOC_TARGETS()
endif()
```

--------------------------------

### Running a Demo Script

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/samples/draw_scripts.md

Example of how to source a demo script from the DRAW prompt using its absolute or CASROOT-relative path.

```Tcl
source $env(CASROOT)/resources/samples/tcl/bottle.tcl
```

--------------------------------

### Create Assembly with Instance using vconnect

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/visualization/visualization.md

Shows how to create an assembly of objects, including an instance, and display them with transformations. The original object does not need to be displayed to create an instance.

```tcl
pload MODELING VISUALIZATION
vinit
psphere s 1
psphere p 0.5
vdisplay s             # p is not displayed
vsetloc s -2 0 0
vconnect x 3 0 0 s p   # make assembly
vfit
```

--------------------------------

### Variable Naming Conventions

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/contribution/coding_rules.md

Variable names should not conflict with global names and should not start with an underscore. Examples show good and bad practices.

```cpp
int Elapsed_Time = 0; // this is bad - possible class   name
int gp = 0;           // this is bad - existing package name
int aGp = 0;          // this is OK
int _KERNEL = 0;      // this is bad
int THE_KERNEL = 0;   // this is OK
```

--------------------------------

### Get Entity Number by Label

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Prints the number for an entity given its label. Labels typically start with '#' for STEP and 'D' for IGES.

```php
enum <#(D)>
```

--------------------------------

### Begin Script Example

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/contribution/tests/tests.md

The 'begin' file is a Tcl script executed before each test in a group. It typically loads Draw commands and sets parameters like CPU time limits.

```tcl
    pload TOPTEST ;# load topological command
    set cpulimit 300 ;# set maximum time allowed for script execution
```

--------------------------------

### Get Unique Attribute ID

Source: https://github.com/open-cascade-sas/occt/wiki/sample_ocaf

Returns the unique GUID for the transformation attribute. This is used for identifying the attribute among others attached to the same label.

```cpp
#include <MyPackage_Transformation.hxx>

//=======================================================================
//function : GetID
//purpose  : The method returns a unique GUID of this attribute.
//           By means of this GUID this attribute may be identified
//           among other attributes attached to the same label.
//=======================================================================
const Standard_GUID& MyPackage_Transformation::GetID()
{
  static Standard_GUID ID("4443368E-C808-4468-984D-B26906BA8573");
  return ID;
}
```

--------------------------------

### Initialize V3d Viewer and Graphic Driver

Source: https://github.com/open-cascade-sas/occt/wiki/visualization

Sets up the visualization environment by creating a display connection, an OpenGL graphic driver, and a V3d viewer. It also configures the viewer's background color and creates a structure for rendering.

```cpp
// create a default display connection
Handle(Aspect_DisplayConnection) aDispConnection = new Aspect_DisplayConnection();
// create a Graphic Driver
Handle(OpenGl_GraphicDriver) aGraphicDriver = new OpenGl_GraphicDriver (aDispConnection);
// create a Viewer to this Driver
Handle(V3d_Viewer) aViewer = new V3d_Viewer (aGraphicDriver);
aViewer->SetDefaultBackgroundColor (Quantity_NOC_DARKVIOLET);
// Create a structure in this Viewer
Handle(Graphic3d_Structure) aStruct = new Graphic3d_Structure (aViewer->StructureManager());
aStruct->SetVisual (Graphic3d_TOS_SHADING); // Type of structure

// Create a group of primitives  in this structure
Handle(Graphic3d_Group) aPrsGroup = aStruct->NewGroup();

// Fill this group with one quad of size 100
Handle(Graphic3d_ArrayOfTriangleStrips) aTriangles = new Graphic3d_ArrayOfTriangleStrips (4);
aTriangles->AddVertex (-100./2., -100./2., 0.0);
aTriangles->AddVertex (-100./2.,  100./2., 0.0);
aTriangles->AddVertex ( 100./2., -100./2., 0.0);
aTriangles->AddVertex ( 100./2.,  100./2., 0.0);

Handle(Graphic3d_AspectFillArea3d) anAspects = new Graphic3d_AspectFillArea3d (Aspect_IS_SOLID, Quantity_NOC_RED,
```

--------------------------------

### vsize Command Example

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Shows how to use the vsize command to set the size of a previously defined object, like a tetrahedron.

```php
vinit 
vtrihedron tr1 
vtrihedron tr2 0 0 0 1 0 0 1 0 0 
vsize tr2 400
```

--------------------------------

### Define a Message File Structure

Source: https://github.com/open-cascade-sas/occt/wiki/shape_healing

Example of an ASCII message file format using keys prefixed with a dot and comments starting with an exclamation mark.

```cpp
!This is a sample message file
!------------------------------
!Messages for ShapeAnalysis package
!
.SampleKeyword
Your message string goes here
!
!...
!
!End of the message file
```

--------------------------------

### OCAF Resource File Example

Source: https://github.com/open-cascade-sas/occt/wiki/sample_ocaf

Defines a new model document 'OCAF-MyApplication', including its description, file extension, and the GUIDs for its storage, retrieval, and schema plugins.

```text
formatlist:OCAF-MyApplication
OCAF-MyApplication.Description: MyApplication Document Version 1.0
OCAF-MyApplication.FileExtension: sta
OCAF-MyApplication.StoragePlugin: ad696000-5b34-11d1-b5ba-00a0c9064368
OCAF-MyApplication.RetrievalPlugin: ad696001-5b34-11d1-b5ba-00a0c9064368
OCAF-MyApplicationSchema: ad696002-5b34-11d1-b5ba-00a0c9064368
OCAF-MyApplication.AttributeStoragePlugin: 47b0b826-d931-11d1-b5da-00a0c9064368
OCAF-MyApplication.AttributeRetrievalPlugin: 47b0b827-d931-11d1-b5da-00a0c9064368
```

--------------------------------

### vdimention Command Examples

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Demonstrates creating length, angle, and radius dimensions using the vdimension command. Note that length dimensions require a working plane.

```php
vinit
vpoint p1 0 0 0
vpoint p2 50 50 0
vdimension dim1 -length -plane xoy -shapes p1 p2
```

```php
vpoint p3 100 0 0
vdimension dim2 -angle -shapes p1 p2 p3
```

```php
vcircle circle p1 p2 p3 0
vdimension dim3 -radius -shapes circle
vfit
```

--------------------------------

### Get Topological Variable from DBRep

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Example of retrieving a TopoDS_Shape object from DBRep using its variable name. This is typically used within a custom Draw command.

```cpp
int MyCommand 
(Draw_Interpretor& theCommands, 
int argc, char** argv) 
{...... 
// Creation of a TopoDS_Shape from a Draw topological 
// name 
TopoDS_Shape aShape = DBRep::Get(argv[1]); 
}
```

--------------------------------

### Initialize VTK Viewer

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Creates a window for the VTK viewer.

```php
ivtkinit
```

--------------------------------

### Get Geometric Variable from DrawTrSurf

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Example of retrieving a Geom_Geometry object from DrawTrSurf using its variable name. This is typically used within a custom Draw command.

```cpp
int MyCommand 
(Draw_Interpretor& theCommands, 
int argc, char** argv) 
{...... 
// Creation of a Geom_Geometry from a Draw geometric 
// name 
occ::handle<Geom_Geometry> aGeom = DrawTrSurf::Get(argv[1]); 
}
```

--------------------------------

### Post-Migration Formatting and Build

Source: https://github.com/open-cascade-sas/occt/blob/master/adm/scripts/migration_800/README.md

Standard commands to format code, build the project, and run tests after migration.

```bash
# Run your CI/CD formatting tool (clang-format)
```

```bash
cmake --build build --config Release
```

```bash
ctest --test-dir build
```

--------------------------------

### Get Nearest Solution Point (Method)

Source: https://github.com/open-cascade-sas/occt/wiki/modeling_algos

Retrieves the solution point that is closest to the original starting point. This method provides direct access to the best-fit point on the curve.

```cpp
gp_Pnt P1 = Projector.NearestPoint(); 

```

--------------------------------

### Get Distance from Start Point to Solution Point

Source: https://github.com/open-cascade-sas/occt/wiki/modeling_algos

Calculates the distance between the initial point and a specific solution point on the curve, identified by its index. This helps in evaluating the accuracy of the projection.

```cpp
Standard_Real D = Projector.Distance(Index); 

```

--------------------------------

### Realtime Initialization and Parameter Modification

Source: https://github.com/open-cascade-sas/occt/wiki/de_wrapper

Demonstrates how to register a node and modify internal parameters using a smart pointer.

```cpp
// global variable
static Handle(STEPCAFControl_ConfigurationNode) THE_STEP_NODE;

static Handle(DE_ConfigurationNode) RegisterStepNode()
{
  Handle(DE_Wrapper) aSession = DE_Wrapper::GlobalWrapper();
  if (!THE_STEP_NODE.IsNull())
  {
    return THE_STEP_NODE;
  }

  THE_STEP_NODE = new STEPCAFControl_ConfigurationNode();
  aSession->Bind(THE_STEP_NODE);
  return THE_STEP_NODE;
}

// Change parameter value
THE_STEP_NODE->InternalParameters.ReadRelationship = false;
THE_STEP_NODE->InternalParameters.ReadName = false;
THE_STEP_NODE->InternalParameters.ReadProps = false;
```

--------------------------------

### Run Demonstration File

Source: https://github.com/open-cascade-sas/occt/wiki/draw_scripts

Executes a Tcl demonstration script provided with Open CASCADE. Replace '<demo_file>' with the desired script name.

```Tcl
source <demo_file>
```

--------------------------------

### DRAW Example: CellsBuilder Initialization and Build

Source: https://github.com/open-cascade-sas/occt/wiki/boolean_operations

Initializes the DRAW environment and performs the CellsBuilder operation on a set of objects. This is a common setup step before applying specific boolean operations.

```php
bclearobjects
bcleartools
baddobjects c s f
bfillds
bcbuild r
```

--------------------------------

### BRep File Example

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/specification/brep_format.md

A sample .brep file demonstrating the structure of drawable shapes, locations, curve data, and polygon data.

```text
    DBRep_DrawableShape  
     
    CASCADE Topology V1, (c) Matra-Datavision  
    Locations 3  
    1  
    					 0						  0						 1						 0   
    					 1						  0						 0						 0   
    					 0						  1						 0						 0   
    1  
    					 1						  0						 0					 4   
    					 0						  1						 0					 5   
    					 0						  0						 1					 6   
    2 1 1 2 1 0  
    Curve2ds 24  
    1 0 0 1 0   
    1 0 0 1 0   
    1 3 0 0 -1   
    1 0 0 0 1   
    1 0 -2 1 0   
    1 0 0 1 0   
    1 0 0 0 -1   
    1 0 0 0 1   
    1 0 0 1 0   
    1 0 1 1 0   
    1 3 0 0 -1   
    1 1 0 0 1   
    1 0 -2 1 0   
    1 0 1 1 0   
    1 0 0 0 -1   
    1 1 0 0 1   
    1 0 0 0 1   
    1 0 0 1 0   
    1 3 0 0 1   
    1 0 0 1 0   
    1 0 0 0 1   
    1 0 2 1 0   
    1 3 0 0 1   
    1 0 2 1 0   
    Curves 13  
    1 0 0 0 0 0 1   
    1 0 0 3 -0 1 0   
    1 0 2 0 0 0 1   
    1 0 0 0 -0 1 0   
    1 1 0 0 0 0 1   
    1 1 0 3 0 1 0   
    1 1 2 0 0 0 1   
    1 1 0 0 -0 1 0   
    1 0 0 0 1 0 -0   
    1 0 0 3 1 0 -0   
    1 0 2 0 1 0 -0   
    1 0 2 3 1 0 -0   
    1 1 0 0 1 0 0   
    Polygon3D 1  
    2 1  
    0.1  
    1 0 0 2 0 0   
    0 1   
    PolygonOnTriangulations 24  
    2 1 2   
    p 0.1 1 0 3   
    2 1 4   
    p 0.1 1 0 3   
    2 2 3   
    p 0.1 1 0 2   
    2 1 2   
    p 0.1 1 0 2   
    2 4 3   
    p 0.1 1 0 3   
    2 1 4   
    p 0.1 1 0 3   
    2 1 4   
    p 0.1 1 0 2   
    2 1 2   
    p 0.1 1 0 2   
    2 1 2   
```

--------------------------------

### Example: Raytracing Activation

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Demonstrates initializing the viewer and enabling raytracing for a displayed object.

```php
vinit
box b 10 10 10
vdisplay b
vfit
vraytrace 1
```

--------------------------------

### Project Point onto Curve on Surface

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Projects a point onto a curve that lies on a surface. The curve is defined by an edge and its face. An optional start parameter can be provided to guide the projection search.

```php
projpcurve <edge> <face>  <Tol> <X> <Y> <Z> [<start_param>]
```

```php
# Using global searching   
projpcurve f_1 f 1.e-7 0.877 0 0.479
==Point: 0.87762772831890712 0 0.47934285275342808
==Param: 0.49990578239977856
==Dist: 0.0007152557954264938
```

```php
# Using starting parameter on edge
projpcurve f_1 f 1.e-7 0.877 0 0.479 .6
==Point: 0.87762772831890712 0 0.47934285275342808
==Param: 0.49990578239977856
==Dist: 0.0007152557954264938
```

--------------------------------

### Create a point cloud

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Initializes the viewer, creates a point cloud with specified parameters, and fits the view.

```tcl
vinit
vpointcloud pc 0 0 0 100 100000 surface -randColor
vfit
```

--------------------------------

### Configure and execute General Fuse algorithm in C++

Source: https://github.com/open-cascade-sas/occt/wiki/boolean_operations

Demonstrates setting up arguments, configuring performance and safety options, and executing the operation using the BOPAlgo_Builder class.

```cpp
BOPAlgo_Builder aBuilder;
// Setting arguments
TopTools_ListOfShape aLSObjects = …; // Objects
aBuilder.SetArguments(aLSObjects);

// Setting options for GF

// Set parallel processing mode (default is false)
Standard_Boolean bRunParallel = Standard_True;
aBuilder.SetRunParallel(bRunParallel);

// Set Fuzzy value (default is Precision::Confusion())
Standard_Real aFuzzyValue = 1.e-5;
aBuilder.SetFuzzyValue(aFuzzyValue);

// Set safe processing mode (default is false)
Standard_Boolean bSafeMode = Standard_True;
aBuilder.SetNonDestructive(bSafeMode);

// Set Gluing mode for coinciding arguments (default is off)
BOPAlgo_GlueEnum aGlue = BOPAlgo_GlueShift;
aBuilder.SetGlue(aGlue);

// Disabling/Enabling the check for inverted solids (default is true)
Standard Boolean bCheckInverted = Standard_False;
aBuilder.SetCheckInverted(bCheckInverted);

// Set OBB usage (default is false)
Standard_Boolean bUseOBB = Standard_True;
aBuilder.SetUseOBB(buseobb);

// Perform the operation
aBuilder.Perform();

// Check for the errors
if (aBuilder.HasErrors())
{
  return;
}

// Check for the warnings
if (aBuilder.HasWarnings())
{
  // treatment of the warnings
  ...
}

// result of the operation
const TopoDS_Shape& aResult = aBuilder.Shape();
```

--------------------------------

### vclipplane Command Example

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Illustrates setting a clipping plane using vclipplane with an equation and applying it to a view. Includes displaying a box and fitting the view.

```php
vinit
vclipplane pln1 -equation 1 0 0 -0.1 -set Driver1/Viewer1/View1
box b 100 100 100
vdisplay b
vsetdispmode 1
vfit
vrotate 10 10 10
vselect 100 100
```

--------------------------------

### Project Point onto Curve on Surface (Tcl)

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Projects a given point onto a curve that lies on a specified face. The curve must have a 2D representation on the face. An optional start parameter can be provided to guide the projection search.

```tcl
projpcurve <edge> <face>  <Tol> <X> <Y> <Z> [<start_param>]
```

--------------------------------

### Configure GF Algorithm Options in C++

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/specification/boolean_operations/boolean_operations.md

Demonstrates how to set various options for the BOPAlgo_Builder, including parallel processing, fuzzy values, safe mode, gluing, inverted solid checks, and OBB usage before performing an operation.

```cpp
BOPAlgo_Builder aBuilder;
// Setting arguments
NCollection_List<TopoDS_Shape> aLSObjects = …; // Objects
aBuilder.SetArguments(aLSObjects);

// Setting options for GF

// Set parallel processing mode (default is false)
bool bRunParallel = true;
aBuilder.SetRunParallel(bRunParallel);

// Set Fuzzy value (default is Precision::Confusion())
double aFuzzyValue = 1.e-5;
aBuilder.SetFuzzyValue(aFuzzyValue);

// Set safe processing mode (default is false)
bool bSafeMode = true;
aBuilder.SetNonDestructive(bSafeMode);

// Set Gluing mode for coinciding arguments (default is off)
BOPAlgo_GlueEnum aGlue = BOPAlgo_GlueShift;
aBuilder.SetGlue(aGlue);

// Disabling/Enabling the check for inverted solids (default is true)
bool bCheckInverted = false;
aBuilder.SetCheckInverted(bCheckInverted);

// Set OBB usage (default is false)
bool bUseOBB = true;
aBuilder.SetUseOBB(bUseOBB);

// Perform the operation
aBuilder.Perform();

// Check for the errors
if (aBuilder.HasErrors())
{
  return;
}

// Check for the warnings
if (aBuilder.HasWarnings())
{
  // treatment of the warnings
  ...
}

// result of the operation
const TopoDS_Shape& aResult = aBuilder.Shape();
```

--------------------------------

### Install Custom Install Script

Source: https://github.com/open-cascade-sas/occt/blob/master/CMakeLists.txt

Installs a custom install script using a template, with a name derived from compiler and bitness settings.

```cmake
set (SUB_CUSTOM_BUILD_NAME "custom_${COMPILER}_${COMPILER_BITNESS}.install.${SCRIPT_EXT}")

# Set custom bin/lib paths variable for template
if (LAYOUT_IS_VCPKG)
  # For vcpkg layout, paths need to handle debug/release structure
  # Debug builds: scripts in debug/bin, need to go ../../ to reach root
  # Release builds: scripts in bin, need to go ../ to reach root
  if (WIN32)
    set (OCCT_CUSTOM_BIN_LIB_PATHS "set \"CSF_OCCTBinPath=%CASROOT%\\bin\"\n    set \"CSF_OCCTLibPath=%CASROOT%\\lib\"\n    if exist \"%SCRIPTROOT%\\..\\..\\include\" (\n      set \"CASCONTENTROOT=%SCRIPTROOT%\\..\\..\"\n    ) else (\n      set \"CASCONTENTROOT=%SCRIPTROOT%\\..\"\n    )\n    set \"CSF_OCCTIncludePath=%CASCONTENTROOT%\\include\"\n    set \"CSF_OCCTResourcePath=%CASCONTENTROOT%\\share\\${OCCT_PROJECT_NAME}\"\n    set \"CSF_OCCTDataPath=%CASCONTENTROOT%\\share\\${OCCT_PROJECT_NAME}\"\n    set \"CSF_OCCTTestsPath=%CASCONTENTROOT%\\share\\${OCCT_PROJECT_NAME}\\tests\"\n    set \"CSF_OCCTDocPath=%CASCONTENTROOT%\\share\\${OCCT_PROJECT_NAME}\\doc\"")
  else()
    set (OCCT_CUSTOM_BIN_LIB_PATHS "export CSF_OCCTBinPath=\"${CASROOT}/bin\"\n    export CSF_OCCTLibPath=\"${CASROOT}/lib\"\n    if [ -d \"${aScriptPath}/../../include\" ]; then\n      export CASCONTENTROOT=$(cd \"${aScriptPath}/../..\" && pwd)\n    else\n      export CASCONTENTROOT=$(cd \"${aScriptPath}/..\" && pwd)\n    fi\n    export CSF_OCCTIncludePath=\"${CASCONTENTROOT}/include\"\n    export CSF_OCCTResourcePath=\"${CASCONTENTROOT}/share/${OCCT_PROJECT_NAME}\"\n    export CSF_OCCTDataPath=\"${CASCONTENTROOT}/share/${OCCT_PROJECT_NAME}\"\n    export CSF_OCCTTestsPath=\"${CASCONTENTROOT}/share/${OCCT_PROJECT_NAME}/tests\"\n    export CSF_OCCTDocPath=\"${CASCONTENTROOT}/share/${OCCT_PROJECT_NAME}/doc\"")
  endif()
  
  # For vcpkg, we handle all paths in the bin/lib paths logic above
  set (OCCT_CUSTOM_ADDITIONAL_PATHS "")
else()
  # For other layouts, use CASROOT with full paths including build-specific suffixes
  if (WIN32)
    set (OCCT_CUSTOM_BIN_LIB_PATHS "set \"CSF_OCCTBinPath=%CASROOT%/${INSTALL_DIR_BIN}%3\"\n    set \"CSF_OCCTLibPath=%CASROOT%/${INSTALL_DIR_LIB}%3\"")
    set (OCCT_CUSTOM_ADDITIONAL_PATHS "set \"CSF_OCCTIncludePath=%CASROOT%/${INSTALL_DIR_INCLUDE}\"\n    set \"CSF_OCCTResourcePath=%CASROOT%/${INSTALL_DIR_RESOURCE}\"\n    set \"CSF_OCCTDataPath=%CASROOT%/${INSTALL_DIR_DATA}\"\n    set \"CSF_OCCTTestsPath=%CASROOT%/${INSTALL_DIR_TESTS}\"\n    set \"CSF_OCCTDocPath=%CASROOT%/${INSTALL_DIR_DOC}\"")
  else()
    set (OCCT_CUSTOM_BIN_LIB_PATHS "export CSF_OCCTBinPath=\"${CASROOT}/${INSTALL_DIR_BIN}\"\n    export CSF_OCCTLibPath=\"${CASROOT}/${INSTALL_DIR_LIB}\"")
    set (OCCT_CUSTOM_ADDITIONAL_PATHS "export CSF_OCCTIncludePath=\"${CASROOT}/${INSTALL_DIR_INCLUDE}\"\n    export CSF_OCCTResourcePath=\"${CASROOT}/${INSTALL_DIR_RESOURCE}\"\n    export CSF_OCCTDataPath=\"${CASROOT}/${INSTALL_DIR_DATA}\"\n    export CSF_OCCTTestsPath=\"${CASROOT}/${INSTALL_DIR_TESTS}\"\n    export CSF_OCCTDocPath=\"${CASROOT}/${INSTALL_DIR_DOC}\"")
  endif()
endif()

OCCT_CONFIGURE_AND_INSTALL ("adm/templates/custom.install.${SCRIPT_EXT}.in" "${SUB_CUSTOM_BUILD_NAME}" "${SUB_CUSTOM_NAME}" "${INSTALL_DIR_SCRIPT}")
```

--------------------------------

### Load Default Plugin Example

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Example of using the 'pload' command without arguments to load the default DrawPlugin and the DEFAULT key, activating basic modeling commands.

```tcl
Draw[]        pload (equivalent to pload -DrawPlugin DEFAULT). 

```

--------------------------------

### vplane Command Example

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Shows how to define a plane using the vplane command, specifying an axis and a point on the plane.

```php
vinit
vpoint p1 0 50 0
vaxis axe1 0 0 0 0 0 1
vtrihedron tr
vplane plane1 axe1 p1
```

--------------------------------

### Install Package Version File

Source: https://github.com/open-cascade-sas/occt/blob/master/CMakeLists.txt

Installs the generated OpenCASCADEConfigVersion.cmake file to the CMake installation directory.

```cmake
install (FILES "${CMAKE_BINARY_DIR}/OpenCASCADEConfigVersion.cmake" DESTINATION "${INSTALL_DIR_CMAKE}")
```

--------------------------------

### BRepGraph Builder Options

Source: https://github.com/open-cascade-sas/occt/blob/master/src/ModelingData/TKBRep/BRepGraph/README.md

Explains the BRepGraph_Builder::Perform() method and the CreateAutoProduct option for controlling root product creation.

```text
After topology population, BRepGraph_Builder::Perform() can auto-create a single root Product wrapping the top-level topology node. This graph-level policy is controlled by BRepGraph_Builder::BuildOptions::CreateAutoProduct (default true), because it is implemented by the builder layer rather than the backend population pipeline. When disabled (e.g. XCAF builder manages Products itself), the caller is responsible for creating Products.
```

--------------------------------

### Install Test Cases

Source: https://github.com/open-cascade-sas/occt/blob/master/CMakeLists.txt

Conditionally installs test cases to the specified installation directory if the INSTALL_TEST_CASES option is enabled.

```cmake
if (INSTALL_TEST_CASES)
  OCCT_INSTALL_FILE_OR_DIR ("tests/" "${INSTALL_DIR_TESTS}")
endif()
```

--------------------------------

### vconnect Command Example

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

Illustrates connecting objects using the vconnect command, specifying a target object and connection parameters.

```php
vinit
vpoint p1 0 0 0
vpoint p2 50 0 0
vsegment segment p1 p2
restore CrankArm.brep obj
vdisplay obj
vconnect new obj 100100100 1 0 0 0 0 1
```

--------------------------------

### Plugin Factory Implementation

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Example of implementing a plug-in library for the Draw Test Harness. It includes the necessary macro to declare the entry point and a factory method to activate commands.

```cpp
#include <Draw_PluginMacro.hxx>

void MyPack::Factory(Draw_Interpretor& theDI)
{
...
// 
MyPack::CurveCommands(theDI);
...
}

// Declare entry point PLUGINFACTORY
DPLUGIN(MyPack)
```

--------------------------------

### Example DrawPlugin Resource File Excerpt

Source: https://github.com/open-cascade-sas/occt/wiki/draw_test_harness

This excerpt shows the structure of a DrawPlugin resource file, defining keys that map to visualization, kernel, and toolkit names.

```plaintext
OCAF               : VISUALIZATION, OCAFKERNEL 
VISUALIZATION      : AISV 
OCAFKERNEL         : DCAF 

DCAF               : TKDCAF 
AISV               : TKViewerTest 

```

--------------------------------

### Build and Install Tk on macOS

Source: https://github.com/open-cascade-sas/occt/wiki/building_3rdparty

Configure, build, and install Tk from source on macOS, linking against the Tcl installation.

```bash
cd TK_SRC_DIR/macosx
```

```bash
configure --enable-gcc --enable-shared --enable-threads --with-tcl=TCL_LIB_DIR --prefix=TK_INSTALL_DIR
```

```bash
make
```

```bash
make install
```

--------------------------------

### Configure and Install Environment Script (Unix-like)

Source: https://github.com/open-cascade-sas/occt/blob/master/CMakeLists.txt

Configures and installs a combined environment script for building and installation on Unix-like systems.

```cmake
OCCT_CONFIGURE_AND_INSTALL ("adm/templates/env.install.${SCRIPT_EXT}.in" "${SUB_ENV_BUILD_NAME}" "${SUB_ENV_NAME}" "${INSTALL_DIR_SCRIPT}")
```

--------------------------------

### Generate HTML Overview Documentation

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/contribution/documentation/documentation.md

Use this CMake target to generate the HTML documentation for the Overview and User Guides. Ensure your build is configured with `-DBUILD_DOC_Overview=ON`.

```bash
cmake --build . --target Overview

```

--------------------------------

### Generate Combined Documentation

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/contribution/documentation/documentation.md

Use this CMake target to generate both the HTML Overview and Reference Manual documentation. Ensure your build is configured with the appropriate documentation options.

```bash
cmake --build . --target doc

```

--------------------------------

### Install Emscripten Build Artifacts

Source: https://github.com/open-cascade-sas/occt/blob/master/src/Draw/DRAWEXE/CMakeLists.txt

Installs the generated HTML, ICO, data, and optional worker.js files for the Emscripten build to the designated installation directory.

```cmake
install(FILES ${PROJECT_NAME}.html
        DESTINATION "${INSTALL_DIR_BIN}/${OCCT_INSTALL_BIN_LETTER}")
install(FILES ../DrawResources/lamp.ico
        DESTINATION "${INSTALL_DIR_BIN}/${OCCT_INSTALL_BIN_LETTER}")
install(FILES ${CMAKE_BINARY_DIR}/${OS_WITH_BIT}/${COMPILER}/bin\${OCCT_INSTALL_BIN_LETTER}/${PROJECT_NAME}.data
        DESTINATION "${INSTALL_DIR_BIN}/${OCCT_INSTALL_BIN_LETTER}")
if (CMAKE_CXX_FLAGS MATCHES "-pthread")
  install(FILES ${CMAKE_BINARY_DIR}/${OS_WITH_BIT}/${COMPILER}/bin\${OCCT_INSTALL_BIN_LETTER}/${PROJECT_NAME}.worker.js
          DESTINATION "${INSTALL_DIR_BIN}/${OCCT_INSTALL_BIN_LETTER}")
endif()
```

--------------------------------

### Vector Algebra Example

Source: https://github.com/open-cascade-sas/occt/blob/master/dox/user_guides/draw_test_harness/draw_test_harness.md

Demonstrates the use of vector algebra commands, including setting vectors, calculating cross products, and finding the module of a vector.

```tcl
Draw[10]> set vec1 [vec 12 28 99 12 58 99]
0 30 0
Draw[13]> set vec2 [vec 12 28 99 16 21 89]
4 -7 -10
Draw[14]> set cross [eval cross $vec1 $vec2]
-300 0 -120
Draw[15]> eval module $cross
323.10988842807024
```

--------------------------------

### Install Deprecated NCollection Alias Headers

Source: https://github.com/open-cascade-sas/occt/blob/master/CMakeLists.txt

Installs deprecated NCollection alias headers from the 'src/Deprecated/NCollectionAliases/' directory to the specified installation destination for backward compatibility.

```cmake
install(DIRECTORY src/Deprecated/NCollectionAliases/
        DESTINATION "${INSTALL_DIR_INCLUDE}")
```

--------------------------------

### Validate and Install Custom Scripts

Source: https://github.com/open-cascade-sas/occt/blob/master/CMakeLists.txt

Checks if custom scripts exist and if additional content needs to be appended before installing them. It uses the OCCT_CONFIGURE_AND_INSTALL macro for the installation process.

```cmake
if (EXISTS "${CMAKE_BINARY_DIR}/custom.${SCRIPT_EXT}" AND EXISTS "${INSTALL_DIR}/${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}")
  file (READ "${INSTALL_DIR}/${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}" CUSTOM_CONTENT)
  string(FIND "${CUSTOM_CONTENT}" "${ADDITIONAL_CUSTOM_CONTENT}" pos)
  if (pos EQUAL -1)
    set (CUSTOM_CONTENT "${CUSTOM_CONTENT} ${ADDITIONAL_CUSTOM_CONTENT}")
    OCCT_CONFIGURE_AND_INSTALL ("adm/templates/custom.${SCRIPT_EXT}.main" "custom.${SCRIPT_EXT}" "custom.${SCRIPT_EXT}" "${INSTALL_DIR_SCRIPT}")
  endif()
else()
  OCCT_CONFIGURE_AND_INSTALL ("adm/templates/custom.${SCRIPT_EXT}.main" "custom.${SCRIPT_EXT}" "custom.${SCRIPT_EXT}" "${INSTALL_DIR_SCRIPT}")
endif()
```