3.2 KiB
Triplanar Node
Description
Triplanar is a method of generating UVs and sampling a texture by projecting in world space. The input Texture is sampled 3 times, once in each of the world x, y and z axises, and the resulting information is planar projected onto the model, blended by the normal, or surface angle. The generated UVs can be scaled with the input Tile and the final blending strength can be controlled with the input Blend. The projection can be modified by overriding the inputs Position and Normal. This is commonly used to texture large models such as terrain, where hand authoring UV coordinates would be problematic or not performant.
The expected type of the input Texture can be switched with the dropdown Type. If set to Normal the normals will be converted into world space so new tangents can be constructed then converted back to tangent space before output.
NOTE: This Node can only be used in the Fragment shader stage.
Ports
| Name | Direction | Type | Binding | Description |
|---|---|---|---|---|
| Texture | Input | Texture | None | Input texture value |
| Sampler | Input | Sampler State | None | Sampler for input Texture |
| Position | Input | Vector 3 | World Space Position | Fragment position |
| Normal | Input | Vector 3 | World Space Normal | Fragment normal |
| Tile | Input | Vector 1 | None | Tiling amount for generated UVs |
| Blend | Input | Vector 1 | None | Blend factor between different samples |
| Out | Output | Vector 4 | None | Output value |
Controls
| Name | Type | Options | Description |
|---|---|---|---|
| Type | Dropdown | Default, Normal | Type of input Texture |
Generated Code Example
The following example code represents one possible outcome of this node.
Default
float3 Node_UV = Position * Tile;
float3 Node_Blend = pow(abs(Normal), Blend);
Node_Blend /= dot(Node_Blend, 1.0);
float4 Node_X = SAMPLE_TEXTURE2D(Texture, Sampler, Node_UV.zy);
float4 Node_Y = SAMPLE_TEXTURE2D(Texture, Sampler, Node_UV.xz);
float4 Node_Z = SAMPLE_TEXTURE2D(Texture, Sampler, Node_UV.xy);
float4 Out = Node_X * Node_Blend.x + Node_Y * Node_Blend.y + Node_Z * Node_Blend.z;
Normal
float3 Node_UV = Position * Tile;
float3 Node_Blend = max(pow(abs(Normal), Blend), 0);
Node_Blend /= (Node_Blend.x + Node_Blend.y + Node_Blend.z ).xxx;
float3 Node_X = UnpackNormal(SAMPLE_TEXTURE2D(Texture, Sampler, Node_UV.zy));
float3 Node_Y = UnpackNormal(SAMPLE_TEXTURE2D(Texture, Sampler, Node_UV.xz));
float3 Node_Z = UnpackNormal(SAMPLE_TEXTURE2D(Texture, Sampler, Node_UV.xy));
Node_X = float3(Node_X.xy + Normal.zy, abs(Node_X.z) * Normal.x);
Node_Y = float3(Node_Y.xy + Normal.xz, abs(Node_Y.z) * Normal.y);
Node_Z = float3(Node_Z.xy + Normal.xy, abs(Node_Z.z) * Normal.z);
float4 Out = float4(normalize(Node_X.zyx * Node_Blend.x + Node_Y.xzy * Node_Blend.y + Node_Z.xyz * Node_Blend.z), 1);
float3x3 Node_Transform = float3x3(IN.WorldSpaceTangent, IN.WorldSpaceBiTangent, IN.WorldSpaceNormal);
Out.rgb = TransformWorldToTangent(Out.rgb, Node_Transform);