Houdini

https://www.sidefx.com/docs/houdini
Admin
Houdini is a powerful 3D animation software known for its procedural workflow, used for visual...
Tokens:10,723,683
Snippets:123,773
Trust Score:10
Update:4 days ago
Show doc for...
Tokens:
Raw
### legacy_install basic usage examples

Source: https://www.sidefx.com/docs/houdini/ref/utils/installermigration.html

Examples showing how to perform online installation using credentials and offline installation from a tarball.

```bash
# Online installation with login credentials
houdini_installer legacy_install \
    --login-file ~/sidefx_credentials.txt \
    --version 22.0.123 \
    --accept-EULA 2021-10-13 \
    --install-houdini \
    --no-install-license \
    /opt/hfs22.0

# Offline installation from a tarball
houdini_installer legacy_install \
    --offline-installer houdini-22.0.123-linux_x86_64_gcc11.3.tar.gz \
    --accept-EULA 2021-10-13 \
    /opt/hfs22.0
```

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

### Installing Engine Maya

Source: https://www.sidefx.com/docs/houdini/ref/utils/installer.html

Example of installing a product name that contains spaces by enclosing it in quotes.

```bash
houdini_installer install --product "Engine Maya"
```

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

### Start a persistent MQ Server

Source: https://www.sidefx.com/docs/houdini/ref/utils/mqserver.html

Example script to start the mqserver as a persistent service with specific relay and callback ports.

```bash
#!/bin/bash
RELAYPORT=53000
HTTP_CALLBACK_PORT=53001
echo "STARTING MQSERVER with RELAY PORT ${RELAYPORT} and HTTP CALLBACK PORT ${HTTP_CALLBACK_PORT}"
/mnt/hq/houdini_distros/hfs.linux-x86_64/bin/mqserver -s -p ${RELAYPORT} -n 1024 -l 2 -w ${HTTP_CALLBACK_PORT} 1024 result
```

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

### Apply Setup Operator

Source: https://www.sidefx.com/docs/houdini/ref/utils/icomposite.html

The setup operator boosts low luminance levels of an image based on its alpha channel. This example shows the syntax for applying the operator to an image file.

```bash
icomposite abekas:34.rgb = setup .075 claw.pic
```

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

### Get collection members

Source: https://www.sidefx.com/docs/houdini/vex/functions/usd_collectioncomputedpaths.html

This example demonstrates how to construct a collection path using usd_makecollectionpath and then retrieve the list of member objects using usd_collectioncomputedpaths.

```VEX
// Get all objects in cube's collection.
string collection_path = usd_makecollectionpath(0, "/geo/cube", "some_collection");
string members[] = usd_collectioncomputedpaths(0, collection_path);
```

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

### Get blurred point position for point cloud lookup

Source: https://www.sidefx.com/docs/houdini/vex/functions/getblurP.html

Example showing how to use getblurP(0) to find the position at the start of the exposure for point cloud lookups.

```vex
vector p0 = getblurP(0);
int handle = pcopen("pcloud.pc", p0, ...);
```

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

### Environment Path Mapping Examples

Source: https://www.sidefx.com/docs/houdini/unity/environment.html

Examples of defining custom environment path keys for different project directories.

```text
HEU_ENVPATH_COMMON_HDAS=C:\\Dev\\Houdini\\CommonAssets
HEU_ENVPATH_PROJECT_AWESOME=C:\\Projects\\Awesome\\HDAs
```

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

### Start Houdini Engine Debugger examples

Source: https://www.sidefx.com/docs/houdini/hom/hou/startHoudiniEngineDebugger.html

Examples showing how to start a debugging session using either a port number or a pipe name.

```python
>hou.startHoudiniEngineDebugger(9090)
>hou.startHoudiniEngineDebugger("hapi_debug_session")
```

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

### Install HQueue Client and Reboot

Source: https://www.sidefx.com/docs/houdini/hqueue/gettingstarted.html

Run these commands to install the HQueue client, configure the server connection, and reboot the machine to finalize the installation.

```bash
# Install the HQueue client.
houdini-X.X.XXX-win64-vcYYY.exe /S /AcceptEULA=20XX-XX-XX /LicenseServer=No /DesktopIcon=No /FileAssociations=No /HoudiniServer=No /SideFXLabs=No /HQueueClient=Yes /HQClientInstallDir=C:\HQueueClient /HQClientServerName=myServer /HQClientServerPort=5000

# Reboot the machine to complete installation.
shutdown /r
```

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

### Start the help server from hython with start_server

Source: https://www.sidefx.com/docs/houdini/help/central.html

Starts the built-in server programmatically. If config_file is None and use_houdini_path is True, it searches the Houdini path for config/Help/bookish.cfg using hou, which may use a batch license. The bgindex argument can be True, False, or None; None uses the configuration value.

```python
from houdinihelp.server import start_server

start_server(
    host="0.0.0.0",         # Network interface to listen to
    port=8080,             # Port to listen to
    debug=False,            # Whether to start the server in debug mode
    bgindex=None ,          # Whether to do background indexing
    config_file=None,       # String path to a config file
    use_houdini_path=True,  # See below
)

```

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

### Check HOUDINI_USER_PREF_DIR from installer and hython

Source: https://www.sidefx.com/docs/houdini/ref/plugins.html

Shows the value of HOUDINI_USER_PREF_DIR when Houdini is started from the installer or desktop versus from hython. The installer path includes 'Documents' while the hython path does not.

```python
# From the installer (or desktop)
>>> import os
>>> os.environ["HOUDINI_USER_PREF_DIR"]
'C:/Users/bob/Documents/houdini21.5'

# From hython
>>> import os
>>> os.environ["HOUDINI_USER_PREF_DIR"]
'C:/Users/bob/houdini21.5'
```

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

### Create a basic web server script

Source: https://www.sidefx.com/docs/houdini/hom/hou/webServer/index.html

A complete example of a server.py file using the hwebserver.urlHandler decorator to respond to requests. Run this script using hython to start the server.

```python
import hou
import hwebserver


@hwebserver.urlHandler("/")
def my_handler(request):
    return hwebserver.Response(
        "Hello from Houdini %s" % hou.applicationVersionString())


if __name__ == "__main__":
    hwebserver.run(8008, debug=True)
```

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

### sesictrl install command options

Source: https://www.sidefx.com/docs/houdini/ref/utils/sesictrl.html

Displays the available options for the install command, used to manually install a license key string.

```text
Install License:
    --license-info <license info>       License information to manually install license.
    --help                              Help with installing licenses.

Host Options [Optional]:
    -h [ --host ] <host>                hostname
```

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

### Run HQueue client installer script

Source: https://www.sidefx.com/docs/houdini/hqueue/gettingstarted.html

Execute the installation script via terminal to complete the HQueue client setup on macOS after using the old Houdini installer.

```bash
sudo /Library/HQueueClient/install.sh
```

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

### sample_bsdf usage example

Source: https://www.sidefx.com/docs/houdini/vex/functions/sample_bsdf.html

Demonstrates how to call sample_bsdf with keyword arguments for illumination control and parameter importing.

```VEX
sample_bsdf(F, inI, outI, eval, type, sx, sy,
    "direct", 0,                        // Specify indirect illumination
    "import:sssmfp", sssmfp,        // Read the exported sssmfp parameter
    ...
);
```

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

### Run the help server with hhelp serve

Source: https://www.sidefx.com/docs/houdini/help/central.html

Starts the built-in help server on all interfaces at port 8080 with background indexing enabled. The --skip-license-modes flag restricts access to commercial, indie, and education licenses. Open a browser to http://localhost:8080/ after starting.

```bash
hhelp --skip-license-modes="commercial,indie,education" serve --host=0.0.0.0 --port=8080 -bgindex=true

```

```text
http://localhost:8080/

```

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

### chprim_start

Source: https://www.sidefx.com/docs/houdini/vex/contexts/displace.html

Get the start time of a channel primitive.

```APIDOC
## chprim_start

### Description
Get the start time of a channel primitive.

### Function Signature
chprim_start(channel)

### Parameters
- **channel** (string) - The channel primitive.

### Returns
- The start time of the channel primitive.
```

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

### chprim_start

Source: https://www.sidefx.com/docs/houdini/vex/contexts/image3d.html

Gets the start time of a channel primitive.

```APIDOC
## chprim_start

### Description
Gets the start time of a channel primitive.

### Usage
`chprim_start(prim)`

### Parameters
- **prim** (int) - The channel primitive.

### Returns
- (float) - The start time.
```

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

### HelpButton.__init__(help_path, tooltip)

Source: https://www.sidefx.com/docs/houdini/hom/hou/qt/HelpButton.html

Creates and returns a new help button that opens the given help when clicked. The help_path must be a recognized help path, and an optional tooltip can be provided.

```APIDOC
## HelpButton.__init__(help_path, tooltip)

### Description
Creates and returns a new help button that opens the given help when clicked.

### Method
Constructor

### Parameters
- **help_path** (string) - Required - A recognized help path, e.g., "/nodes/sop/torus" to open the Torus SOP help.
- **tooltip** (string) - Optional - Hover tooltip text for the button. Default is "Show help for this window".

### Returns
A new HelpButton instance.

### Example
```python
button = hou.qt.HelpButton("/nodes/sop/torus", tooltip="Open Torus SOP help")
```
```

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

### chprim_start

Source: https://www.sidefx.com/docs/houdini/vex/contexts/chop.html

Gets the start time of a channel primitive.

```APIDOC
## chprim_start

### Description
Gets the start time of a channel primitive.

### Signature
chprim_start(geohandle, prim)

### Parameters
- **geohandle** (string) - The geometry handle.
- **prim** (integer) - The primitive number.

### Returns
- Start time (float)
```

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

### hou.qt.ToolTip.__init__()

Source: https://www.sidefx.com/docs/houdini/hom/hou/qt/ToolTip.html

Create and return a new tooltip window.

```APIDOC
## hou.qt.ToolTip.__init__()

### Description
Create and return a new tooltip window.

### Method
Constructor

### Parameters
None

### Returns
A new tooltip window object.
```

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

### Get and Set Viewport Layout

Source: https://www.sidefx.com/docs/houdini/hom/hou/geometryViewportLayout.html

Example showing how to get the current viewport layout and change it to a quad view using the SceneViewer object.

```APIDOC
## Get and Set Viewport Layout

### Description
This example demonstrates how to retrieve the current viewport layout and change it to a quad view using the SceneViewer object.

### Code Example
```python
# Get a reference to the 3D viewer pane tab
desktop = hou.ui.curDesktop()
viewer = desktop.paneTabOfType(hou.paneTabType.SceneViewer)

# Get the current layout
current_layout = viewer.viewportLayout()
# Change the layout to "quad view"
viewer.setViewportLayout(hou.geometryViewportLayout.Quad)
```
```

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

### Example project.json Configuration

Source: https://www.sidefx.com/docs/houdini/solaris/shotbuilder.html

This configuration file defines project-wide defaults and specific unit types like 'shot' and 'env', including their respective sublayers and naming templates.

```json
{
  "project": {
    "name": "myProject",              \\ project name
    "unit_context_option": "shot",    \\ context option to drive current shot
    "default_fps": "24.0",            \\ default fps for all units in project
    "default_start_frame": "1001",    \\ default start frame for all units in project
    "default_end_frame": "1020",      \\ default end frame for all units in project
    "sublayer_format": "usda",        \\ default USD format for unit layers in project
    "version_padding": 4,             \\ version padding for versioned files (see HPR Paths)
    "unit_templates": {               \\ this is where you define various unit types
      "shot": {                       \\ defines 'shot' unit type
        "name": "s%04d",                 \\ name template for shot units (printf)
        "icon": "shotIcon",              \\ icon for the 'shot' unit type
        "fps": "24.0",                   \\ 'shot' unit override for default_fps
        "start_frame": "1001",           \\ 'shot' unit override for default_start_frame
        "end_frame": "1024",             \\ 'shot' unit override for default_end_frame
        "sublayer_format": "usd",        \\ 'shot' unit override for project sublayer_format
        "sublayers": {                   \\ list of sublayers 'shot' units should have
          "./lighting.usda": {                  \\ relative reference to lighting.usda
            "name": "Shot Lighting",                \\ display name
            "comment": "shot lighting layer",       \\ comment
            "icon": "lightingIcon"                  \\ icon
          },
          "./animation.usda": {                 \\ relative reference to lighting.usda
            "name": "Shot Animation",               \\ display name
            "comment": "shot animation layer",      \\ comment
            "icon": "animationIcon"                 \\ icon
          },
          "./layout.usda": {                    \\ relative reference to lighting.usda
            "name": "Shot Layout",                  \\ display name
            "comment": "shot layout layer",         \\ comment
            "icon": "layoutIcon"                    \\ icon
          },
          "__env__": {}                         \\ placeholder for 'env' type unit
        }
      },
      "env": {                                  \\ define 'env' unit type
        "name_template": "env",
        "sublayers": {
          "./layout.usda": {
            "name": "Env Assets",
            "comment": "environment assets layer",
            "icon": "envIcon"
          }
        }
      }
    },
    "non_versioned_folders": [                  \\ Non versioned folders (See HPR Paths)
        "/nonVersioned/"
    ]
  }
}
```

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

### Graph functions example setup

Source: https://www.sidefx.com/docs/houdini/character/kinefx/apexscriptfunctions.html

Provides the definitions used in the graph functions examples: creates an ApexGraphHandle and adds two TransformObject nodes to the graph.

```python
graph = ApexGraphHandle()

# Add two TransformObject nodes to the graph
a = graph.addNode('test_a', 'TransformObject')
b = graph.addNode('test_b', 'TransformObject')
```

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

### sesictrl partition-info example

Source: https://www.sidefx.com/docs/houdini/ref/utils/sesictrl.html

Displays information about the current partition info used by the listed sesinetd server.

```bash
sesictrl partition-info
```

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

### parent example

Source: https://www.sidefx.com/docs/houdini/hom/hou/ApexNode.html

Shows how to get the parent node of a node using hou.Node.parent. The example prints the parent of a node and demonstrates that the root node returns None.

```python
>>> hou.node("/obj/box_object1").parent()
<hou.Node at /obj>
>>> print hou.node("/").parent()
None

```

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

### Sampling lights using create_cdf

Source: https://www.sidefx.com/docs/houdini/vex/functions/create_cdf.html

This example demonstrates how to calculate the power of lights, create a CDF from those values, and use sample_cdf to randomly select a light based on its power distribution.

```VEX
// Iterate over all lights, sampling their power
int[] li = getlights();
float values[];
resize(values, len(li));
int nsamples = 256;
int sid = israytrace ? SID : newsampler();
vector s, pos, clr;
float scale;
for (int i = 0; i < len(li); i++)
{
    for (int j = 0; j < nsamples; j++)
    {
        nextsample(sid, s.x, s.y, "mode", "nextpixel");
        sample_light(li[i], P, s, Time, pos, clr, scale);
        values[i] += luminance(clr);
    }
    values[i] /= nsamples;
}

// Create a CDF of the power distribution
float cdf[] = create_cdf(values);

// Randomly select a light based on power distribution
nextsample(sid, s.x, s.y, "mode", "nextpixel");
int index = 0;
sample_cdf(cdf, s.x, index);

// Do something with the selected light
// li[index] ...
```

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

### Install Subcommand Syntax

Source: https://www.sidefx.com/docs/houdini/ref/utils/installer.html

The syntax for installing a new product or version using the install subcommand.

```bash
houdini_installer [options] install [install_options] --product <<product>> --version <<version>> [--installdir <<installdir>>]
```

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

### URLHandler.methods property

Source: https://www.sidefx.com/docs/houdini/hwebserver/URLHandler_class.html

The list of methods (GET, POST, etc) the URLHandler is installed on.

```APIDOC
## URLHandler.methods property

### Description
The list of methods (GET, POST, etc) the URLHandler is installed on.

### Property
`methods`
```

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

### Example Linux Network Configuration

Source: https://www.sidefx.com/docs/houdini/hqueue/configuration.html

A sample configuration for a Linux-based farm defining HQROOT and PROJECT_PATH.

```ini
[HQROOT]
linux = /mnt/hq

[PROJECT_PATH]
linux = /mnt/project
```
Tokens:
Raw