Method prepareProgramMaterial

src/PackedSplats.ts:757–802

(generator: GsplatGenerator)

  // Get a program and THREE.RawShaderMaterial for a given GsplatGenerator,
  // generating it if necessary and caching the result.
  prepareProgramMaterial(generator: GsplatGenerator): {
    program: DynoProgram;
    material: THREE.RawShaderMaterial;
  } {
    let program = PackedSplats.generatorProgram.get(generator);
    if (!program) {
      // A Gsplat needs to be turned into a packed uvec4 for the dyno graph
      const graph = dynoBlock(
        { index: "int" },
        {},
        ({ index }, _outputs, { roots }) => {
          generator.inputs.index = index;
          const gsplat = generator.outputs.gsplat;
          const output = outputPackedSplat(
            gsplat,
            this.dynoRgbMinMaxLnScaleMinMax,
          );
          roots.push(output);
          return undefined;
        },
      );
      if (!PackedSplats.programTemplate) {
        PackedSplats.programTemplate = new DynoProgramTemplate(
          getShaders().computeUvec4Template,
        );
      }
      // Create a program from the template and graph
      program = new DynoProgram({
        graph,
        inputs: { index: "_index" },
        outputs: { output: "target" },
        template: PackedSplats.programTemplate,
      });
      Object.assign(program.uniforms, {
        targetLayer: { value: 0 },
        targetBase: { value: 0 },
        targetCount: { value: 0 },
      });
      PackedSplats.generatorProgram.set(generator, program);
    }

    // Prepare and update our material we'll use to render the Gsplats
    const material = program.prepareMaterial();
    PackedSplats.fullScreenQuad.material = material;
    return { program, material };
  }

  private saveRenderState(renderer: THREE.WebGLRenderer) {
    return {