WebGLObjects: Optimize InstancedMesh updates.

[Mugen87]

Related issue: #26293

Description

I've noticed updating InstancedMesh can be improved by checking the frame value similar to how geometries are updated.

The PR also refactors the skeleton update by removing Skeleton.frame. The frame is now stored in the internal update map of WebGLObjects.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
642.8 kB (159.4 kB)	642.8 kB (159.4 kB)	-16 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

Filesize dev	Filesize PR	Diff
436.1 kB (105.6 kB)	436.1 kB (105.6 kB)	-2 B

[Amatewasu]

Hi @Mugen87, thanks for the improvement.

With @TeoAvignon, we are trying to upgrade the three.js version of our project and it appears that the v154 breaks our mouseenter and other mouse related events on InstancedMesh. We think it is related to this change.

We struggle to create a minimal reproductive case though.

The following piece of code triggers well the onPointerOver events with three v153 but not in v154. (sorry it has been written with react-three-fiber)

<instancedMesh
          ref={
            stocklinesMeshRef as Ref<
              THREE.InstancedMesh<THREE.BufferGeometry, THREE.RawShaderMaterial | THREE.RawShaderMaterial[]>
            >
          }
          args={[undefined, undefined, nMaxSlot]}
          onPointerOver={(e) => {
            const instanceId = e.instanceId;
            const stocklineId = instanceId !== undefined ? instanceIdToStocklineId.current.get(instanceId) : undefined;
            setHovered(stocklineId !== undefined ? { id: stocklineId.id, position: stocklineId.position } : null);
          }}
          onClick={handleClick}
          onPointerLeave={() => setHovered(null)}
          frustumCulled={false}
        >
          <planeGeometry attach="geometry" args={[1, 1, 1]}>
            <instancedBufferAttribute attach="attributes-uvOffset" args={[uvOffset, 2]} />
            <instancedBufferAttribute attach="attributes-opacity" args={[opacity, 1]} />
          </planeGeometry>
          <rawShaderMaterial
            opacity={stocklinesOpacity}
            transparent
            depthWrite={false}
            onBeforeCompile={(shader) => {
              shader.uniforms.map = { value: textureAtlas };
              shader.uniforms.atlasRows = { value: atlasRows };
              shader.uniforms.atlasColumns = { value: atlasColumns };

              shader.vertexShader = vertexShader;
              shader.fragmentShader = fragmentShader;
            }}
          />
        </instancedMesh>

Would you have an idea on what could lead to this change?
(we tested with simpler materials and simpler geometries and in our project the behavior stay the same)

We will try to update the issue with a codesandbox as soon as we have something to reproduce.

[Mugen87]

It's best if you ask for help at the forum first. If it turns out to be a bug in the engine, open a new issue.

I doubt that this particular PR introduces the regression. Maybe the bounding volume addition in r151 has an unexpected side effect in your app. Whenever you transform instances of InstancedMesh, make sure to update the bounding volumes via computeBoundingBox() and computeBoundingSphere(). Otherwise they don't reflect the real bounds of the instanced mesh which could lead to unexpected culling or buggy raycasting.

[TeoAvignon]

That's absolutely this ! Computing the BBox and BSphere gives back the previous behavior we had.
Thank you very much for your quick reply @Mugen87 !

Have a good day !