Objective

Add a test for mipmap filters, and as a bonus test GltfLoaderSettings::override_sampler. Neither of these are covered by current tests or examples.

Solution

The test supports CI screenshots, although I haven't added it to the CI config.

Problems

It's currently broken.

• The test works by loading the same glTF multiple times, each time changing GltfLoaderSettings::override_sampler.
• That falls afoul of Gltf assets do not reload correctly #18267.
• I've confirmed that the test does work if the assets are duplicated. This can be reproduced in the PR branch by syncing to faefb8dd.

Combining two tests into one is debatable.

• Testing GltfLoaderSettings::override_sampler is convenient and provides a test case for Gltf assets do not reload correctly #18267.
• But makes it harder to isolate bugs.
• And gltf tests should aim to be headless.
• Maybe this is ok for now but gets refactored later.

CI screenshot boilerplate.

• Screenshot supports feels a bit boilerplate-y. It's fairly similar to testbed/helpers.rs.
• My guess is that this whole test will eventually get replaced by a BSN scene.
• Or maybe the CI testing could have a helper that queues up N screenshots and sends an event for each one.

Testing

cargo run --example gltf_override_sampler
cargo run --example test_mipmap_filter --features bevy_ci_testing

Tested on Win10/Nvidia, across Desktop/Vulkan, Chrome/WebGL, Chrome/WebGPU.