May I ask how to do multi pass? Do you have an example

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1

May I ask how to do multi pass? Do you have an example

2

It’s not directly supported … even though most likely can be done by using Layers. What are you trying to do?

3

occ

I need to create this effect, which requires 2 passes,

First pass. depthWrite = false; depthFunc=FUNC_GREATER, rendering occluded parts

Second pass. depthWrite = true; depthFunc=FUNC_LESSEQUAL, rendering normal parts

5

Something like this could work:

  • find a mesh instance of that mesh. It has pointer to material, mesh, skinInstance, and a node.
  • you need to create a duplicate material, with your different depth settings.
  • you need to create a new mesh instance, using this duplicate material, mesh, the same node, and the same skin instance (if the mesh is skinned)
  • then you need a layer, that renders after your original layer, and using Layer.addMeshInstances to add your new mesh instance to it.
6

In this case, I need to control two identical instances to do the same animation. If there are 10 characters in my scene, there should be problems in performance.

7

As long as you use the same skinInstance on the meshInstance, it’d use already evaluated skin matrices for it, without extra cost.

8

thanks, i’ll try

9

we have some internal code which does something similar … perhaps based it on this:

const revealageBlend = new BlendState(true, BLENDEQUATION_ADD, BLENDMODE_ZERO, BLENDMODE_ONE_MINUS_SRC_COLOR);

        const newMeshInstances = model.entity.findComponents('render').map((component: RenderComponent) => {
            return component.meshInstances.map((meshInstance) => {
                if (meshInstance?.material?.blendType === BLEND_NONE) {
                    return null;
                }

                const accumMaterial = meshInstance.material as StandardMaterial;
                accumMaterial.blendState = accumBlend;
                accumMaterial.chunks = {
                    outputAlphaPS: accumPS
                };

                // copy the material so we can customize the alpha blending
                const revealageMaterial = new StandardMaterial();
                revealageMaterial.copy(accumMaterial);
                revealageMaterial.blendState = revealageBlend;
                revealageMaterial.chunks = {
                    outputAlphaPS: revealagePS
                };

                // construct a new mesh instance
                return new MeshInstance(meshInstance.mesh, revealageMaterial, meshInstance.node);
            }).filter(a => a);
        }).flat();

        this.revealageLayer.addMeshInstances(newMeshInstances);

but additionally, you need something along:

cloneMeshInstance.skinInstance = meshInstance.skinInstance;

and in addition to blendState, assign custom DepthState as well.

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