Update `IndexDatatype.createTypedArray` to create Uint8Arrays

[j9liu]

Currently IndexDatatype.createTypedArray only outputs Uint16Array and Uint32Array. This caused a bug in #10344 because it returned a Uint16Array for uint8 indices, which was too big for the getBufferData function. The fix itself is easy but it causes a lot of unit tests to break, which will take more time to fix.

Once this function is changed to return Uint8Array, the manual check in buildDrawCommands can be removed to accommodate this.

[malitherl]

Hello, may I be assigned to work on this issue?

[j9liu]

Hi @malitherl,

Thanks for your interest in contributing! For smaller issues (like those labeled "good first issue"), there's no need to ask for permission. It's customary to comment on the issue or start a thread on our forum for larger features or code changes, but this one shouldn't be too sizeable. You can work on the issue and open a pull request for review when ready.

If you have any questions, you can comment on the issue or on the PR itself if it's far enough along to open. There's also a lot of standard documentation in the Contributors folder if you need guidance.

[Harjot4698]

hie @malitherl, If you are seeing this message , please reply

[acharyasourav]

Hey @j9liu I've made the necessary changes but I need some help with the test case as I'm new to this. Please check the pull request #10505

[rravula77]

Hello, my team and I would like to work on the issue

[ggetz]

Great @rravula77! Let us know if you have any questions or would like to discuss the approach.

[Charlyjcmu]

I am part of rahul's team. We are a little confused on how to change the test cases. Many of the errors are due to the expected render not matching the actual render. Should we be copying the actual render to the expected render or should we be calculating if the output is correct?

We don't really understand what is a render or a scene, so we don't understand how to calculate the correct render. Where can we learn more about this?

[ggetz]

Hi there, a "render" is the process by which a single frame or image is created., while the "scene" is a top-level object which generally defines what is being rendered. To understand how it's used in unit testing, check out the Rendering Tests section of our Testing Guide to learn more.

Would you also mind posting the test errors so we can help troubleshoot the specifics?

[Charlyjcmu]

So most of the failed render test cases are failing due the pixel not matching, We are a little confused on how to correct for this error.

There is also a hidden GL_INVALID_OPERATION: Insufficient buffer size warning.

Could you help us figure out where the error is coming from? .

[j9liu]

This is no longer a trivial issue, as found in #10955:

The problem with the unit tests comes from rendering problems with the geometry itself. The changes have caused holes in some of the geometry:

main	this branch

This is what happens in the 3D Tiles Terrain Classification sandcastle (which uses Vector3DTileContent). This also happens in the ArcticDEM sandcastle.

Much of the code automatically assumes that indices can only be uint16 or uint32, so resolving this may require changes across all of CesiumJS's rendering code.