# ibl_sample

**Repository Path**: wangzhuohw/ibl_sample

## Basic Information

- **Project Name**: ibl_sample
- **Description**: Sample showing how to use IBL(image based lighting) in arkgraphics 3d.
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-02-15
- **Last Updated**: 2025-02-15

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

## 添加IBL光照步骤
### 1. HDR转成Cubemap(KTX)
将.hdr文件放置到``tools/hdr2ibl``目录，执行``tools/hdr2ibl/convert.bat``脚本

### 2. 加载资产
将生成出来的两张ktx图片放置到``entry\src\main\resources\rawfile``资产目录，并替换如下代码片段：
```
          this.scene.environment.environmentImage = await rf.createImage({
            name: "skybox",
            uri: $rawfile('IBL/flower_road_2k_skybox.ktx')
          });
          this.scene.environment.radianceImage = await rf.createImage({
            name: "radiance",
            uri: $rawfile('IBL/flower_road_2k_ibl.ktx')
          });
```
其中，``skybox``贴图表示天空显示的颜色，``radiance``贴图表示天空对物体的光照。

### 3. 设置球谐参数
HDR的光照信息一部分存储在``radiance``贴图，另一部分用球谐函数表示。将步骤1生成出来的``sh.txt``中的球谐参数替换到如下代码段中(可使用DeepSeek工具辅助调整格式)：
```
          this.scene.environment.irradianceCoefficients =
            [
              { x: 1.588075518608093, y: 1.513368964195251, z: 1.448706507682800 }, // L00, irradiance, pre-scaled base
              { x: 1.519405007362366, y: 1.558451414108276, z: 1.578060746192932 }, // L1-1, irradiance, pre-scaled base
              { x: 1.504220962524414, y: 1.463262438774109, z: 1.383159756660461 }, // L10, irradiance, pre-scaled base
              { x: -1.298253297805786, y: -1.258347153663635, z: -1.182270407676697 }, // L11, irradiance, pre-scaled base
              { x: -1.305838108062744, y: -1.261003851890564, z: -1.181669354438782 }, // L2-2, irradiance, pre-scaled base
              { x: 1.493174433708191, y: 1.444317102432251, z: 1.358674407005310 }, // L2-1, irradiance, pre-scaled base
              { x: -0.003305336227641, y: 0.002338147023693, z: 0.005189759656787 }, // L20, irradiance, pre-scaled base
              { x: -1.190836310386658, y: -1.143299579620361, z: -1.069862723350525 }, // L21, irradiance, pre-scaled base
              { x: -0.169978946447372, y: -0.153091773390770, z: -0.136493653059006 }  // L22, irradiance, pre-scaled base
            ];
```