Non-prefiltered cubemap is ignored if scene has prefiltered skybox

[Maksims]

Description

If the scene has prefiltered skybox, then applying non-prefiltered cubemap onto material is ignored.

Steps to Reproduce:

1. Create new project from Model View Starter Kit
2. Open Editor
3. Download "Milky Way" from Asset Store to the project
4. Select "Milky Way" cubemap
5. Hit "Delete Prefiltered Data"
6. Apply "Milky Way" cubemap on "plastic-orange" material.

Issue:

Applied cubemap is ignored. Visually nothing happens.

Solution:

Ensure cubemap is applied, regardless of prefilter data. It is expected that cubemap to be used without prefiltered information on material, and scene skybox to be ignored completelly.

[willeastcott]

@slimbuck I can confirm this still happens as @Maksims describes. What do you consider to be the desired behavior here?

[slimbuck]

Just tried this. The issue appears to be in the editor only - launch page uses cubemap correctly. (And reloading editor tab also results in correct cubemap in editor).

[willeastcott]

I suspect this is an engine issue. From a quick investigation, lines of suspicion:

https://github.com/playcanvas/engine/blob/main/src/framework/handlers/material.js#L188

https://github.com/playcanvas/engine/blob/main/src/framework/handlers/material.js#L274

[willeastcott]

Possibly related: #358