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Custom material expression in UE5

Simple material expression with an input and an output.

Get the code

$ shadeup-unreal
 > [MATERIAL] Custom Material Nodes
 > Base Function

Usage

1. Generate the template: shadeup -> [MATERIAL] Custom Material Nodes -> Base Function
2. Rebuild your project
3. Add the node in a material graph

Sample snippet

int32 UMaterialExpression${NAME}::Compile( FMaterialCompiler* Compiler, int32 OutputIndex)
{
	int32 Result=INDEX_NONE;

	// Check if the input is hooked up, Input is a member we defined in the header for this material expresion.
	// Note: You can define more than one input.

	if( !Input.GetTracedInput().Expression )
	{
		// an input expression must exist
		Result = Compiler->Errorf( TEXT("Missing ${NAME} input") );
	}
	else
	{
		// We get references to inputs/expressions in the form of an int32.
		// These can be passed around and operated on using the FMaterialCompiler::* functions.
		// A list of these functions can be found here: https://docs.unrealengine.com/5.0/en-US/API/Runtime/Engine/FMaterialCompiler/

		// First we store a reference to the input expression.
		int32 InputValue = Input.Compile(Compiler);

		// Then cast to a float3 to ensure the input is a vector.
		int32 InputVector = Compiler->ForceCast(InputValue, MCT_Float3);

		// Then get the length^2 of the vector.
		int32 DotResult = Compiler->Dot(InputVector, InputVector);

		// Then sqrt the result.
		int32 RootResult = Compiler->SquareRoot(DotResult);

		// Finally, we return the result.
		Result = RootResult;
	}

	return Result;
}