WebGLRenderer: Improve `RGBA_INTEGER` support.

[Yao Hsiao]

Description

I face the same issue that @gkjohnson mentioned 3 years ago. Seems the error comes from three.js doesn't support clearing or rendering to integer render targets (as Garrett Johnson said). Any update for this issue?
https://arc.net/l/quote/gnimfrqg

Reproduction steps

Please check the fiddle, you can compare the different between RGBAFormat and RGBAIntegerFormat in console panel.

Code

See fiddle for complete example.

const data = new Uint8Array(2 * 3 * 4)
const texture = new THREE.DataTexture(data, 2, 3)
// texture.format = THREE.RGBAFormat // this work
texture.format = THREE.RGBAIntegerFormat // this not work
texture.type = THREE.UnsignedByteType
texture.minFilter = THREE.NearestFilter
texture.magFilter = THREE.NearestFilter
texture.needsUpdate = true

const renderTarget = new THREE.WebGLRenderTarget(2, 3)
renderTarget.texture = texture
renderer.setRenderTarget(renderTarget)

Live example

https://jsfiddle.net/yaohsiao/np97zdve/21/

Screenshots

Version

r166

Device

Desktop

Browser

Chrome

OS

MacOS

[Michael Herzog]

Related #22351 and #26249.

[Michael Herzog]

There are a couple of issue in your code. Here is a fixed version: https://jsfiddle.net/5hyf3jzo/1/

• You have to define the internal format of the texture, in your case: texture.internalFormat = 'RGBA8UI'.
• Your fragment shader has to render the correct data type. In your case it is uvec4.

Next time, please ask for help at the forum first.

[Garrett Johnson]

It's possible that glInternalFormat could be a bit smarter here. It looks like integer types are handled more gracefully for Red and RG formats but not for RGBA.

[Michael Herzog]

That sounds like a good addition. Would you make a PR with your suggestion?

[Garrett Johnson]

That sounds like a good addition. Would you make a PR with your suggestion?

Perhaps at some point but I don't think I can commit time to implementing and testing it right now. It may be worth keeping the issue open to keep track of it for the moment.