Three.js: Override Material: Morph Targets

[vanruesc]

Description of the problem

I'm using MeshNormalMaterial and MeshDepthMaterial as override materials and I sometimes set morphTargets to true. Now in [email protected], this setting prevents objects without morph targets from being rendered altogether.

I'm not sure if this behaviour is intentional but since this change hasn't been documented I thought I should let you know.

Sandbox

Uncomment line 23 in index.js:
https://codesandbox.io/s/override-material-morph-targets-06hjw

Three.js version

• [x] Dev
• [x] r111
• [ ] r110
• [ ] r109
• [ ] ...

Browser

• [x] All of them
• [ ] Chrome
• [ ] Firefox
• [ ] Internet Explorer

OS

• [ ] All of them
• [x] Windows
• [ ] macOS
• [ ] Linux
• [ ] Android
• [ ] iOS

[Mugen87]

I can confirm this worked with R110. The regression was probably introduced via #17649.

[Mugen87]

Simplified example:

R110: https://jsfiddle.net/aoLbzj1s/
R111: https://jsfiddle.net/aoLbzj1s/1/

The problem is that setting morphTargets to true does not render the mesh when the geometry contains no morph targets. With R110 the mesh is still rendered.

@zeux It seems the uniform morphTargetBaseInfluence still needs an update even if no morph targets are defined. Adding this code in WebGLRenderer.renderBufferDirect() seems to fix the fiddle:

if ( material.morphTargets === true && object.morphTargetInfluences === undefined ) {

    program.getUniforms().setValue( _gl, 'morphTargetBaseInfluence', 1 );

}

Can you think of a better way fixing this? Maybe we can refactor WebGLMorphtargets.update() so it is called when morphTargets is set to true (and not when morphTargetInfluences is defined).

[zeux]

Yeah we definitely need to always set the base influence if the material being used has the morph target shader variant. I will take a look...

[vanruesc]

FYI: the same problem occurs when morphNormals is set to true in MeshNormalMaterial.