What does surfc do?

surfc(X, Y, Z) draws a shaded surface and overlays contour lines projected onto the XY plane. RunMat reuses the same surface renderer as surf and complements it with GPU-generated iso-lines.

GPU behaviour

• Single-precision gpuArrays stream directly into the shared WebGPU renderer.
• Double-precision data falls back to the CPU path until SHADER_F64 is available.