WebGPU: Resizing `RenderTarget3D` converts its texture from `texture_3d` to `texture_2d_array`

[shotamatsuda]

Description

Resizing RenderTarget3D sets the isArrayTexture flag on its texture, and subsequent calls to textureSample on it cannot resolve overloaded functions. Manually setting isArrayTexture to false after resizing works around this issue.

Reproduction steps

1. Resize a RenderTarget3D using setSize().
2. Build a new node to sample its texture with texture3D and a vec3.
3. Open the developer console and see the error message: no matching call to 'textureSample(texture_2d_array<f32>, sampler, vec3<f32>)'.

Code

material.fragmentNode = texture3D(renderTarget.texture).sample(vec3(0, 0, 0))
material.needsUpdate = true
void renderer.render(scene, camera)

// Resize the render target:
renderTarget.setSize(11, 11, 11)

material.fragmentNode = texture3D(renderTarget.texture).sample(vec3(0, 0, 0))
material.needsUpdate = true
void renderer.render(scene, camera)

See also the fiddle below.

Live example

https://jsfiddle.net/shotamatsuda/fpvz0Lbm/

Screenshots

No response

Version

r179

Device

Desktop

Browser

Chrome

OS

Windows, MacOS

[Mugen87]

this.textures[ i ].isArrayTexture = this.textures[ i ].image.depth > 1;

This line is indeed problematic. It's not correct to assume an array texture just because the image has a depth larger than 0.

@RenaudRohlinger Can this flag be set somewhere else in a different context where you know that the texture belongs to an "array" context?

[Mugen87]

When thinking about this, it's strange that setSize() sets a flag like isArrayTexture. setSize() should really focus on resizing and not changing the semantics/type of a render target texture.

[shotamatsuda]

Although I don't fully understand how array textures and 3D textures are organized, given that Texture assumes an array texture when depth is greater than zero, it seems that overriding setSize on RenderTarget3D might be a safe approach, as its texture should always be Data3DTexture.

[Mugen87]

As a first step, that sounds good. I hope we can still get the isArrayTexture flag out of setSize() somehow...