bool PreprocessShader ( [FString](API\Runtime\Core\Containers\FString) & OutPreprocessedShader, [FShaderCompilerOutput](API\Runtime\RenderCore\FShaderCompilerOutput) & ShaderOutput, const [FShaderCompilerInput](API\Runtime\RenderCore\FShaderCompilerInput) & ShaderInput, const [FShaderCompilerDefinitions](API\Runtime\RenderCore\FShaderCompilerDefinitions) & AdditionalDefines, [EDumpShaderDefines](API\Developer\ShaderPreprocessor\EDumpShaderDefines) DefinesPolicy )