Remove WebGLMultisampleRenderTarget.

[Mugen87]

Related issue: #23444 (comment)

Description

This PR removes WebGLMultisampleRenderTarget and introduces WebGLRenderTarget.samples instead.

WebGLRenderTarget.samples is 0 by default and can only be used with WebGL 2. If set, it triggers the multisample render target code path.

I was able to integrate the properties ignoreDepthForMultisampleCopy, useRenderToTexture and useRenderbuffer into the renderer so only samples is added to WebGLRenderTarget.

I've tested the change with the multisampling examples but not with WebXR yet. The WEBGL_multisampled_render_to_texture code path is only used by Oculus Browser so far.

Updated the build files for testing: https://raw.githack.com/Mugen87/three.js/dev62/examples/index.html

/cc @cabanier @arpu

[cabanier]

This change is breaking WebXR.
I'm getting a crash in:
const renderTargetProperties = renderer.properties.get( renderTargetProperties );

[Mugen87]

Tested with a Quest 2 today, too. Examples work as expected.

@vanruesc Do you mind testing this change in your project, too?

[vanruesc]

I've just tested it and can confirm that it works.

I did run into [.WebGL-0x1ec401258700] GL_INVALID_OPERATION: Texture is immutable. under certain circumstances, but I think that was due to a misconfiguration on my side which worked fine with WebGLMultisampleRenderTarget for some reason.

[mrdoob]

Hmm, if I understand the PR correctly... Reflector will now no longer work in WebGL 1 (unless the user specifies multisample: 1) and it will log a warning in the console right?

[Mugen87]

I did run into [.WebGL-0x1ec401258700] GL_INVALID_OPERATION: Texture is immutable. under certain circumstances,

This warning is related to the texStorage() API. It usually appears when a texture is defined with a certain dimension via texStorage2D() and later updated with a larger dimension via texSubImage2D() (which is not valid).

It's the responsibility of the app that a textures dimensions does not change after its initial use.

Reflector will now no longer work in WebGL 1 (unless the user specifies multisample: 1) and it will log a warning in the console right?

Yes. However, the user has to specify a multisample of 0 to deactivate multisampling. And this already happens without the PR.

[Mugen87]

@marcofugaro For some reasons the unit tests now fail at GitHub with the message:

message: "No tests matched the filter "!-webonly"."

Do you know why this suddenly happens?

[mrdoob]

Reflector will now no longer work in WebGL 1 (unless the user specifies multisample: 1) and it will log a warning in the console right?

Yes. However, the user has to specify a multisample of 0 to deactivate multisampling. And this already happens without the PR.

I think we should follow what we do with texture.anisotropy where the user can set it to 16 and the renderer will do as much as the GPU supports.

So if the user sets rendertarget.samples to 4 the renderer will try to use multisample, otherwise it will render without and it'll look aliased.

That way the user doesn't have to check for support and things will continue working.

[marcofugaro]

For some reasons the unit tests now fail at GitHub with the message:

@Mugen87 I did the trick of removing -r failonlyreporter (not ideal I know, should be changed):

Looks like tests were broken in #23460, the MathUtils import must have the .js extension.

[Mugen87]

So if the user sets rendertarget.samples to 4 the renderer will try to use multisample, otherwise it will render without and it'll look aliased.

Okay, I've implemented it like suggested. Meaning the renderer does not report an error if the app tries to use multisampling without WebGL 2. The renderer just ignores the multisampling settings and uses a default render target configuration.

[mrdoob]

Thanks thanks!

[arpu]

tested on production with r138 and all works fine