WebGPURenderer: Issues with PMREM Background.

[Mugen87]

Description

When working at the environment map, I've noticed two issues:

1. When an environment map is assigned to Scene.background, the background node is always a PMREMNode which is not right. When no background blurriness is applied, the cube map format should be used. Since this is not the case, you can spot quality differences in the background when comparing below examples:

• https://threejs.org/examples/webgl_loader_gltf
• https://threejs.org/examples/webgpu_loader_gltf

Here is the code that always produces a PMREM node:

three.js/src/renderers/common/nodes/Nodes.js

Lines 271 to 274 in bde222e

	if ( background.isCubeTexture === true || ( background.mapping === EquirectangularReflectionMapping || background.mapping === EquirectangularRefractionMapping ) ) {
	backgroundNode = pmremTexture( background, normalWorld );

2. Sometimes when loading a page with a textured background, the texture isn't rendered at all and is black. When refreshing the page, the issue disappears. This does not happen if the code waits until the env map has been loaded (like in webgpu_loader_gltf). However, the new webgpu_materials_basic does not so it can be used as a test case.

Reproduction steps

• Open https://threejs.org/examples/webgl_loader_gltf and https://threejs.org/examples/webgpu_loader_gltf
• Compare backgrounds

Version

r167

Device

Desktop

Browser

Chrome

OS

MacOS