### Install ComfyUI Gaussian Preview

Source: https://github.com/yichengup/comfyui-gaussian_preview/blob/main/README.md

Clone the repository into the ComfyUI custom_nodes directory to install the node.

```bash
cd ComfyUI/custom_nodes
git clone https://github.com/your-username/ComfyUI-gaussian_preview.git
```

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

### Frontend Preview Control API

Source: https://context7.com/yichengup/comfyui-gaussian_preview/llms.txt

Demonstrates how to interact with the preview window using postMessage for recording and data loading.

```javascript
// 预览窗口控件功能：

// 1. Scale 缩放控制 (0.01 - 100)
// 调整高斯点云的显示比例，实时生效
gaussianScaleValue.value = 1.0;  // 默认值
// 输入新值后自动应用到所有高斯点

// 2. Reset View 重置视角
// 点击按钮重置相机到初始位置（基于 intrinsics/extrinsics）
document.getElementById('resetCamera').click();

// 3. Max (s) 最大录制时长 (1-600秒)
maxRecordTime.value = 30;  // 默认30秒

// 4. Start Record / Stop Record 视频录制
// 录制格式：MP4 (H.264)
// 帧率：30 FPS
// 码率：5 Mbps
// 分辨率：与预览窗口一致（由 preview_width 参数控制）

// 视频录制消息通信示例：
window.addEventListener('message', (event) => {
    if (event.data.type === 'VIDEO_RECORDING') {
        // event.data.video: Base64 编码的视频数据
        // event.data.mimeType: 'video/mp4'
        // event.data.timestamp: 录制时间戳
        console.log('视频大小:', event.data.video.length);
    }
});

// 加载 PLY 数据消息格式：
iframe.contentWindow.postMessage({
    type: "LOAD_MESH_DATA",
    data: arrayBuffer,          // PLY 文件的 ArrayBuffer
    filename: "model.ply",      // 文件名
    extrinsics: extrinsicsMatrix,  // 4x4 相机外参
    intrinsics: intrinsicsMatrix,  // 3x3 相机内参
    timestamp: Date.now()
}, "*", [arrayBuffer]);
```

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

### Initialize Gaussian Viewer and Listen for Messages

Source: https://github.com/yichengup/comfyui-gaussian_preview/blob/main/web/viewer_gaussian.html

Initializes the viewer and sets up a message listener to receive mesh data, extrinsics, and intrinsics from a parent window for loading. Logs viewer readiness.

```javascript
og('\[GaussianViewer\] originalScales:', !!originalScales); } } scaleInput.addEventListener('change', (e) => updateGaussianScale(e.target.value)); // Event listeners document.getElementById('resetCamera').addEventListener('click', resetCamera); // 截图按钮已删除，事件监听器已移除 // document.getElementById('screenshot').addEventListener('click', takeScreenshot); // Listen for messages from parent window.addEventListener('message', (event) => { const { type, data, filename, extrinsics, intrinsics } = event.data; if (type === 'LOAD\_MESH\_DATA' && data) { console.log('\x5BGaussianViewer\x5D Received LOAD\_MESH\_DATA, size:', data.byteLength); console.log('\x5BGaussianViewer\x5D Extrinsics:', extrinsics); console.log('\x5BGaussianViewer\x5D Intrinsics:', intrinsics); loadPLYFromData(data, filename || 'gaussian.ply', extrinsics, intrinsics); } }); // Initialize on load initViewer(); console.log('\x5BGaussianViewer\x5D Ready - waiting for LOAD\_MESH message');
```

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

### Integrate with ComfyUI-Sharp

Source: https://github.com/yichengup/comfyui-gaussian_preview/blob/main/README.md

Workflow representation for connecting the SHARP Predict node to the Gaussian Preview node.

```text
[Load Image] → [SHARP Predict] → [Preview Gaussian]
                                    ↓
                              [video_path 输出]
```

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

### Preview Gaussian Node Configuration

Source: https://context7.com/yichengup/comfyui-gaussian_preview/llms.txt

Defines the input structure and camera parameter matrices for the YCGaussianPreview node.

```python
# 基本使用 - 从 PLY 文件路径加载
# 在 ComfyUI 工作流中连接节点

# 节点输入参数：
# - ply_path (STRING, 可选): 高斯点云 PLY 文件路径
# - gaussians (GAUSSIANS_3D, 可选): 来自 SHARP Predict 的高斯对象
# - extrinsics (EXTRINSICS, 可选): 4x4 相机外参矩阵
# - intrinsics (INTRINSICS, 可选): 3x3 相机内参矩阵
# - preview_width (INT, 默认512): 预览窗口宽度 (256-4096px)

# 节点输出：
# - video_path (STRING): 最新录制视频的文件路径
# - save_ply_path (STRING): PLY 文件保存路径

# 工作流示例 1: 使用 ComfyUI-Sharp
# [Load Image] → [SHARP Predict] → [Preview Gaussian]
#                                        ↓
#                                  video_path → [下游节点]

# 工作流示例 2: 直接加载 PLY 文件
# [String Input: "/path/to/model.ply"] → [Preview Gaussian]

# 相机参数格式示例：
extrinsics = [
    [1.0, 0.0, 0.0, 0.0],  # R11, R12, R13, tx
    [0.0, 1.0, 0.0, 0.0],  # R21, R22, R23, ty
    [0.0, 0.0, 1.0, 0.0],  # R31, R32, R33, tz
    [0.0, 0.0, 0.0, 1.0]   # 齐次坐标
]

intrinsics = [
    [512.0, 0.0, 512.0],   # fx, 0, cx (cx = image_width/2)
    [0.0, 512.0, 512.0],   # 0, fy, cy (cy = image_height/2)
    [0.0, 0.0, 1.0]        # 0, 0, 1
]
```

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

### Integrate with ComfyUI-GeometryPack

Source: https://github.com/yichengup/comfyui-gaussian_preview/blob/main/README.md

Workflow representation for connecting GeometryPack nodes to the Gaussian Preview node.

```text
[相关几何节点] → [高斯点云生成] → [Preview Gaussian]
                                      ↓
                                [video_path 输出]
```

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

### 初始化 gsplat.js 查看器与渲染循环

Source: https://context7.com/yichengup/comfyui-gaussian_preview/llms.txt

设置 WebGL 渲染环境、场景、相机及轨道控制器，并启动渲染循环以实现实时交互。

```javascript
// 初始化 gsplat.js 查看器
const SPLAT = window.GSPLAT;

// 创建场景、相机、渲染器和控制器
const scene = new SPLAT.Scene();
const camera = new SPLAT.Camera();
const renderer = new SPLAT.WebGLRenderer(canvas);
const controls = new SPLAT.OrbitControls(camera, canvas);

// 设置默认焦距
camera.data.fx = 30;  // 水平焦距
camera.data.fy = 30;  // 垂直焦距

// 渲染循环
function frame() {
    controls.update();
    renderer.render(scene, camera);
    requestAnimationFrame(frame);
}
frame();

// 从 ArrayBuffer 加载 PLY 文件
async function loadPLYFromData(arrayBuffer, filename) {
    const blob = new Blob([arrayBuffer], { type: 'application/octet-stream' });
    const blobUrl = URL.createObjectURL(blob);

    await SPLAT.PLYLoader.LoadAsync(blobUrl, scene);

    URL.revokeObjectURL(blobUrl);

    // 获取加载的高斯点云对象
    const splat = scene.objects[scene.objects.length - 1];

    // 访问高斯点云数据
    console.log('高斯点数量:', splat.data.scales.length / 3);
    console.log('场景中心:', splat.bounds.center());
    console.log('场景尺寸:', splat.bounds.size());
}

// 设置相机位置和目标
function setCameraFromExtrinsics(extrinsics, intrinsics, splat) {
    // 从 4x4 外参矩阵提取相机位置
    const R = [
        [extrinsics[0][0], extrinsics[0][1], extrinsics[0][2]],
        [extrinsics[1][0], extrinsics[1][1], extrinsics[1][2]],
        [extrinsics[2][0], extrinsics[2][1], extrinsics[2][2]]
    ];
    const t = [extrinsics[0][3], extrinsics[1][3], extrinsics[2][3]];

    // 相机位置 = -R^T * t
    const camPosX = -(R[0][0]*t[0] + R[1][0]*t[1] + R[2][0]*t[2]);
    const camPosY = -(R[0][1]*t[0] + R[1][1]*t[1] + R[2][1]*t[2]);
    const camPosZ = -(R[0][2]*t[0] + R[1][2]*t[1] + R[2][2]*t[2]);

    // 从内参计算焦距缩放
    const fx = intrinsics[0][0];
    const imageWidth = intrinsics[0][2] * 2;
    const scale = canvas.clientWidth / imageWidth;

    camera.data.fx = fx * scale;
    camera.data.fy = fx * scale;

    camera.position.x = camPosX;
    camera.position.y = -camPosY;  // Y轴翻转
    camera.position.z = camPosZ;

    controls.setCameraTarget(new SPLAT.Vector3(0, 0, targetZ));
}
```

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

### Frontend Preview Control API

Source: https://context7.com/yichengup/comfyui-gaussian_preview/llms.txt

API for controlling the interactive preview window and video recording features via JavaScript and `postMessage`.

```APIDOC
## Frontend Preview Control API

### Description
This API describes the controls available in the preview window's footer, which allow real-time adjustment of Gaussian Splatting display and video recording. Communication between the frontend controls and the backend nodes is handled via the `postMessage` mechanism.

### Controls and Functionality

1.  **Scale Control**
    *   **Range**: 0.01 - 100
    *   **Functionality**: Adjusts the display scale of the Gaussian Splatting model. Changes are applied in real-time.
    *   **Example**: `gaussianScaleValue.value = 1.0;` (Sets the default value)

2.  **Reset View Button**
    *   **Functionality**: Resets the camera to its initial position, determined by the `intrinsics` and `extrinsics` parameters.
    *   **Example**: `document.getElementById('resetCamera').click();`

3.  **Max Record Time Input**
    *   **Range**: 1 - 600 seconds
    *   **Default**: 30 seconds
    *   **Functionality**: Sets the maximum duration for video recordings.
    *   **Example**: `maxRecordTime.value = 30;`

4.  **Start Record / Stop Record Buttons**
    *   **Functionality**: Initiates or terminates video recording.
    *   **Format**: MP4 (H.264 codec)
    *   **Frame Rate**: 30 FPS
    *   **Bitrate**: 5 Mbps
    *   **Resolution**: Matches the preview window size (controlled by `preview_width`).

### Message Communication Examples

**Receiving Video Recording Data:**
```javascript
window.addEventListener('message', (event) => {
    if (event.data.type === 'VIDEO_RECORDING') {
        // event.data.video: Base64 encoded video data
        // event.data.mimeType: 'video/mp4'
        // event.data.timestamp: Recording timestamp
        console.log('Video size:', event.data.video.length);
    }
});
```

**Sending PLY Data to Load:**
```javascript
iframe.contentWindow.postMessage({
    type: "LOAD_MESH_DATA",
    data: arrayBuffer,          // PLY file's ArrayBuffer
    filename: "model.ply",      // Filename
    extrinsics: extrinsicsMatrix,  // 4x4 camera extrinsic matrix
    intrinsics: intrinsicsMatrix,  // 3x3 camera intrinsic matrix
    timestamp: Date.now()
}, "*", [arrayBuffer]);
```
```

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

### Preview Gaussian Node (YCGaussianPreview)

Source: https://context7.com/yichengup/comfyui-gaussian_preview/llms.txt

The main node for previewing and recording Gaussian Splatting models within ComfyUI. It supports loading data from PLY file paths or GAUSSIANS_3D objects and handles camera parameters for accurate perspective.

```APIDOC
## Preview Gaussian Node (YCGaussianPreview)

### Description
This node displays and records 3D Gaussian Splatting models in ComfyUI. It can load data from PLY file paths or GAUSSIANS_3D objects, automatically processing camera parameters to restore the original viewpoint. It also provides video recording capabilities.

### Method
(Custom Node - No direct HTTP method)

### Endpoint
(Custom Node - Operates within ComfyUI)

### Parameters
#### Input Parameters
- **ply_path** (STRING, Optional) - Path to the Gaussian Splatting PLY file.
- **gaussians** (GAUSSIANS_3D, Optional) - Gaussian object from SHARP Predict.
- **extrinsics** (EXTRINSICS, Optional) - 4x4 camera extrinsic matrix.
- **intrinsics** (INTRINSICS, Optional) - 3x3 camera intrinsic matrix.
- **preview_width** (INT, Default: 512) - Width of the preview window (range: 256-4096px).

#### Output Parameters
- **video_path** (STRING) - File path of the latest recorded video.
- **save_ply_path** (STRING) - File path where the PLY file is saved.

### Workflow Examples
**Example 1: Using ComfyUI-Sharp**
`[Load Image] -> [SHARP Predict] -> [Preview Gaussian]`
`                                        |
                                        V
                                  video_path -> [Downstream Node]`

**Example 2: Loading PLY File Directly**
`[String Input: "/path/to/model.ply"] -> [Preview Gaussian]`

### Camera Parameter Format Examples
```python
extrinsics = [
    [1.0, 0.0, 0.0, 0.0],
    [0.0, 1.0, 0.0, 0.0],
    [0.0, 0.0, 1.0, 0.0],
    [0.0, 0.0, 0.0, 1.0]
]

intrinsics = [
    [512.0, 0.0, 512.0],
    [0.0, 512.0, 512.0],
    [0.0, 0.0, 1.0]
]
```
```

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

### Save PLY Node Configuration

Source: https://context7.com/yichengup/comfyui-gaussian_preview/llms.txt

Outlines the input parameters and usage scenarios for the SavePLYNode to persist Gaussian data.

```python
# 节点输入参数：
# - ply_path (STRING, 可选): 现有 PLY 文件路径，直接返回
# - gaussians (GAUSSIANS_3D, 可选): 需要保存的高斯对象
# - extrinsics (EXTRINSICS, 可选): 相机外参（用于元数据）
# - intrinsics (INTRINSICS, 可选): 相机内参（用于提取焦距和图像尺寸）
# - output_prefix (STRING, 默认"gaussians"): 输出文件名前缀

# 节点输出：
# - ply_path (STRING): 保存的 PLY 文件完整路径

# 使用场景 1: 保存 SHARP 生成的高斯对象
# [SHARP Predict] → gaussians → [Save PLY] → ply_path → [Preview Gaussian]

# 使用场景 2: 传递已有 PLY 文件
# [String: "model.ply"] → ply_path → [Save PLY] → ply_path (原样返回)

# 输出文件命名格式：{output_prefix}_{timestamp}.ply
# 示例：gaussians_1704067200000.ply
# 文件保存位置：ComfyUI 输出目录 (output/)
```

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

### Save PLY Node (SavePLYNode)

Source: https://context7.com/yichengup/comfyui-gaussian_preview/llms.txt

Converts and saves GAUSSIANS_3D objects to PLY files, or passes through existing PLY file paths. Useful for persisting Gaussian Splatting data.

```APIDOC
## Save PLY Node (SavePLYNode)

### Description
This node converts GAUSSIANS_3D objects into PLY files for persistent storage. It can also pass through existing PLY file paths without modification. It supports including camera extrinsic and intrinsic metadata.

### Method
(Custom Node - No direct HTTP method)

### Endpoint
(Custom Node - Operates within ComfyUI)

### Parameters
#### Input Parameters
- **ply_path** (STRING, Optional) - Path to an existing PLY file. If provided, this path is returned directly.
- **gaussians** (GAUSSIANS_3D, Optional) - The Gaussian object to be saved.
- **extrinsics** (EXTRINSICS, Optional) - Camera extrinsic matrix (4x4) to be included as metadata.
- **intrinsics** (INTRINSICS, Optional) - Camera intrinsic matrix (3x3) used to extract focal length and image dimensions for metadata.
- **output_prefix** (STRING, Default: "gaussians") - Prefix for the output PLY filename.

#### Output Parameters
- **ply_path** (STRING) - The full path to the saved PLY file.

### Usage Scenarios
**Scenario 1: Saving a Gaussian Object from SHARP**
`[SHARP Predict] -> gaussians -> [Save PLY] -> ply_path -> [Preview Gaussian]`

**Scenario 2: Passing Through an Existing PLY File**
`[String: "model.ply"] -> ply_path -> [Save PLY] -> ply_path (Returned as is)`

### Output File Naming
Files are named using the format: `{output_prefix}_{timestamp}.ply`.
Example: `gaussians_1704067200000.ply`
Files are saved in the ComfyUI output directory (`output/`).
```

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