MDLAsset loads texture in usdz file loaded with wrong colorspace

Question

achandlerwhite OP

Created Nov ’24

Replies 3

Boosts 2

Participants 3

I have a very basic usdz file from this repo

I call loadTextures() after loading the usdz via MDLAsset. Inspecting the MDLTexture object I can tell it is assigning a colorspace of linear rgb instead of srgb although the image file in the usdz is srgb.

This causes the textures to ultimately render as over saturated.

In the code I later convert the MDLTexture to MTLTexture via MTKTextureLoader but if I set the srgb option it seems to ignore it.

This significantly impacts the usefulness of Model I/O if it can't load a simple usdz texture correctly. Am I missing something?

Thanks!

Answered by DTS Engineer in 818643022

Hi,

FWIW I can't reproduce the issue with Reality Composer Pro or the Xcode viewer.

It's unclear what's going with the transfer function (gamma vs linear) and/or jpeg support without more details.

Since this may be a defect in ModelIO or Metal, please file a bug report with the Feedback Assistant. To help expedite attach a focused sample project that demonstrates this issue.

Also of note, jpeg format doesn't support an alpha channel.

Boost

Answer 1

HangmingFan OP

4w

Facing the same issue. MTKTextureLoader.Option.SRGB option does not work and the loaded texture object always has _isLinearTexture=false (in my case the textures are in jpg format).

0

Answer 2

DTS Engineer OP

Apple

2w

Recommended

Hi,

FWIW I can't reproduce the issue with Reality Composer Pro or the Xcode viewer.

It's unclear what's going with the transfer function (gamma vs linear) and/or jpeg support without more details.

Since this may be a defect in ModelIO or Metal, please file a bug report with the Feedback Assistant. To help expedite attach a focused sample project that demonstrates this issue.

Also of note, jpeg format doesn't support an alpha channel.

0

Answer 3

achandlerwhite OP

2w

Thanks for looking into it. I will file a feedback as you requested.

Regarding the xcode viewer and reality compose they display the texture just fine. Even macOS preview does.

It‘s just in a custom app using model IO (about as basic as possible) the texture colors are saturated.

Thanks again.

0