Shader |
A UsdShade Shader prim representing a processing node. In SPG, a shader is either a custom node (wrapping a CUDA kernel and Lua launch script through info:spg:sourceAsset) or a built-in node (identified through info:id). Inputs can be resource-inputs connected to AOVs (opaque) or value-inputs carrying typed values (int, float, bool). |
Lua Launch Script |
The .lua file named after the GPU source and sitting beside it, GrayscaleKernel.cu.lua for a CUDA node and GrayscaleKernel.slang.lua for a Slang one. Called per frame to validate inputs, describe the outputs, and return a launch configuration. |
subIdentifier |
The info:spg:sourceAsset:subIdentifier attribute on a Shader. Names the entry point in the GPU source, an extern "C" function on CUDA or a [shader(...)] entry point on Slang, and the Lua function to invoke. Optional: without it the Shader prim’s own name is used for both. |
shape |
A resource’s dimensions, as a Lua table with one entry per dimension. Height-first for images: shape[1] is height, shape[2] is width. Refer to Shapes and Types. |
rank |
How many dimensions a resource has, which is how many entries its shape holds. |
dtype |
What one element of a resource is: the kind of number, its width in bits, and how many of them make an element. A dtype is a value taken from the cuda or slang table, such as cuda.uchar4 or slang.float, not a type name. It can be compared against another dtype and called to wrap a value for the GPU. Refer to Shapes and Types. |
