Rasagar/Library/PackageCache/com.unity.shadergraph/Documentation~/Sample-Texture-2D-LOD-Node.md
2024-08-26 23:07:20 +03:00

59 lines
2.7 KiB
Markdown

# Sample Texture 2D LOD Node
## Description
Samples a **Texture 2D** and returns a **Vector 4** color value for use in the shader. You can override the **UV** coordinates using the **UV** input and define a custom **Sampler State** using the **Sampler** input. Use the **LOD** input to adjust the level of detail of the sample.
To use the **Sample Texture 2D LOD Node** to sample a normal map, set the **Type** dropdown parameter to **Normal**.
This [Node](Node.md) is useful for sampling a **Texture** in the vertex [Shader Stage](Shader-Stage.md) as the [Sample Texture 2D Node](Sample-Texture-2D-Node.md) is unavailable in this [Shader Stage](Shader-Stage.md).
On platforms that do not support this operation, opaque black is returned instead.
If you experience texture sampling errors while using this node in a graph which includes Custom Function Nodes or Sub Graphs, you can resolve them by upgrading to version 10.3 or later.
## Ports
| Name | Direction | Type | Binding | Description |
|:------------ |:-------------|:-----|:---|:---|
| Texture | Input | Texture 2D | None | Texture 2D to sample |
| UV | Input | Vector 2 | UV | UV coordinates |
| Sampler | Input | Sampler State | Default sampler state | Sampler for the texture |
| LOD | Input | Float | None | Level of detail to sample |
| RGBA | Output | Vector 4 | None | Output value as RGBA |
| R | Output | Float | None | red (x) component of RGBA output |
| G | Output | Float | None | green (y) component of RGBA output |
| B | Output | Float | None | blue (z) component of RGBA output |
| A | Output | Float | None | alpha (w) component of RGBA output |
## Controls
| Name | Type | Options | Description |
|:------------ |:-------------|:-----|:---|
| Type | Dropdown | Default, Normal | Selects the texture type |
## Generated Code Example
The following example code represents one possible outcome of this node per **Type** mode.
**Default**
```
float4 _SampleTexture2DLOD_RGBA = SAMPLE_TEXTURE2D_LOD(Texture, Sampler, UV, LOD);
float _SampleTexture2DLOD_R = _SampleTexture2DLOD_RGBA.r;
float _SampleTexture2DLOD_G = _SampleTexture2DLOD_RGBA.g;
float _SampleTexture2DLOD_B = _SampleTexture2DLOD_RGBA.b;
float _SampleTexture2DLOD_A = _SampleTexture2DLOD_RGBA.a;
```
**Normal**
```
float4 _SampleTexture2DLOD_RGBA = SAMPLE_TEXTURE2D_LOD(Texture, Sampler, UV, LOD);
_SampleTexture2DLOD_RGBA.rgb = UnpackNormalRGorAG(_SampleTexture2DLOD_RGBA);
float _SampleTexture2DLOD_R = _SampleTexture2DLOD_RGBA.r;
float _SampleTexture2DLOD_G = _SampleTexture2DLOD_RGBA.g;
float _SampleTexture2DLOD_B = _SampleTexture2DLOD_RGBA.b;
float _SampleTexture2DLOD_A = _SampleTexture2DLOD_RGBA.a;
```