EffectPass introduces facing problems with InstancedGeometry

Hello!

I premise that I have not yet been able to reproduce the bug on a codesandbox because the model I am using is in a special format and I have to ask the client I am working for to export a gltf one. As soon as I can I’ll do that, in the meantime I’ll expose the problem I’m experiencing, maybe we don’t even need the demo.

I am using a simple pipeline with RenderPass + EffectPass[BloomEffect], to render a lowpoly model as shown in the attached image. Basically it is a model of a rock made up of several pieces, to which I will then have to apply an animation for the explosion (I think this info is not very relevant)

This model must be reproduced several times, so I am using an InstancedBufferGeometry.

The bug consists of a strange rendering of the mesh faces, in particular these strange artefacts increase as the distance from the camera increases. as shown in the figure. In particular the problem only occurs when I use the EffectPass, even when it has no effect and is therefore “empty”. If I only use RenderPass instead, there is no problem whatsoever

I am already aware of the possible problems with InstancedBufferGeometry and the use of the OverrideMaterialManager, but using only the BloomEffect should not be the case, right? (in any case the bug exists even with workaroundEnabled)

I don’t seem to be doing strange things at the code level

OverrideMaterialManager.workaroundEnabled = true;
...
const renderer = new THREE.WebGLRenderer({ canvas: this.canvas, context: this.gl, powerPreference: 'high-performance', antialias: false, stencil: false, depth: false });
...
this.composer = new EffectComposer(this.renderer, {
	frameBufferType: THREE.HalfFloatType,
	multisampling: 8,
});

this.renderPass = new RenderPass(this.scene, this.camera);
this.composer.addPass(this.renderPass);

this.bloomEfx = new BloomEffect({
	mipmapBlur: true,
});
this.effectPass = new EffectPass(this.camera, this.bloomEfx);
this.composer.addPass(this.effectPass);

The doubt came to me that this is a model-related problem. But then I cannot explain the different behaviour with and without EffectPass.

Library versions used

• Three: ^0.143.0
• Post Processing: ^6.28.5

Thank you!

[vanruesc]

I had to change the default depth texture type back to UnsignedIntType in postprocessing@6.28.7 because the previous switch to UnsignedInt248Type caused another issue with multisampling due to a missing stencil buffer.

I recommend enabling stencilBuffer explicitly if you require at least 24 bits of depth precision on any device. Otherwise try to tune your camera near/far plane settings to still produce satisfactory results with lower precision if possible.

[vanruesc]

With stencilBuffer set to true, the EffectComposer uses UnsignedInt248Type instead for the depth texture which absolutely has to be supported by all devices. I’m considering using that as the new default now that there’s actually a reported case of UnsignedIntType failing.