Triplanar Node

Description

Generates UVs and samples a texture by projecting in world space. This method is commonly used to texture large models such as terrain, where hand authoring UV coordinates would either be problematic or not performant. Samples the input Texture 3 times, once in each of the world x, y, and z axes. The resulting information is planar projected onto the model, blended by the normal, or surface angle. You can scale the generated UVs with the input Tile and you can control the final blending strength with the input Blend.

Blend controls the way the normal affects the blending of each plane sample and should be greater than or equal to 0. The larger Blend is, the more contribution will be given to the sample from the plane towards which the normal is most oriented. (The maximum blend exponent is between 17 and 158 depending on the platform and the precision of the node.) A Blend of 0 makes each plane get equal weight regardless of normal orientation.

To choose the projection, change the Input Space. You can also modify the projection via the inputs Position and Normal.

Use the Type dropdown to change the expected type of the input Texture. If set to Normal, the Out port returns the blended normals in Normal Output Space.

If you experience texture sampling errors while using this node in a graph which includes Custom Function Nodes or Sub Graphs, upgrade to version 10.3 or later.

NOTE: You can only use the Triplanar Node 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	Input Space Position	Fragment position
Normal	Input	Vector 3	Input Space Normal	Fragment normal
Tile	Input	Float	None	Tiling amount for generated UVs
Blend	Input	Float	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

Node Settings Controls

The following controls appear on the Node Settings tab of the Graph Inspector, when you select the Triplanar Node.

Name	Type	Options	Description
Input Space	Dropdown	Object, View, World, Tangent, AbsoluteWorld	Controls the coordinate space used by the input ports Position and Normal. When you change the Input Space value, it changes the bindings on the Position and Normal ports to use the specified space. The default value is AbsoluteWorld.
Normal Output Space	Dropdown	Object, View, World, Tangent, AbsoluteWorld	Controls the coordinate space used for the Out port. The Normal Output Space control is only available when Type is set to Normal. The default value is Tangent.

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);

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