Adds styling for ModelExperimental and ModelExperimental3DTileContent

[sanjeetsuhag]

Supersedes #9826

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• 3D Tiles - CDB Yemen Sandcastle

• 3D Tiles - B3DM Sandcastle

• 3D Tiles - glTF Sandcastle

• glTF Sandcastle using featureIdAttributeIndex = 1

• glTF Sandcastle using featureIdAttributeIndex = 0

• glTF Sandcastle using feature ID textures

• Models without features

• 3D Tiles without features

[cesium-concierge]

Thanks for the pull request @sanjeetsuhag!

• ✔️ Signed CLA found.
• ❔ CHANGES.md was not updated.
  • If this change updates the public API in any way, please add a bullet point to CHANGES.md.
• ❔ Unit tests were not updated.
  • Make sure you've updated tests to reflect your changes, added tests for any new code, and ran the code coverage tool.

Reviewers, don't forget to make sure that:

• Cesium Viewer works.
• Works in 2D/CV.

[ptrgags]

@sanjeetsuhag the sandcastle works fine. I had some questions and comments about the code

[sanjeetsuhag]

@ptrgags Addressed your feedback.

[ptrgags]

@sanjeetsuhag just one note to prevent exposing private API while this is still experimental

[ptrgags]

@sanjeetsuhag looks good to me.

@lilleyse do you want to do a review pass before we merge?

[lilleyse]

@sanjeetsuhag do you have a sandcastle that tests styling on an individual model?

[sanjeetsuhag]

@sanjeetsuhag do you have a sandcastle that tests styling on an individual model?

@lilleyse Here you go

[lilleyse]

Looks much better from the architecture side. The main thing that's missing here, at least from the reviewer side, is sandcastles that more honestly test the behavior of code. What I would have liked to see is a sandcastle that tests styles that are fully opaque, fully translucent, and an opaque/translucent mix with the ability to select them from a dropdown. Also an option for "No style" to see what happens if a style is unset and then later set again. And a dropdown to change the color blend mode. Then I would like to see it working for 3D Tiles with features, individual models with features, 3D Tiles without features, and individual models without features, and some mix of feature id textures and feature id attributes. Without getting too deep into the code myself a sandcastle like that would really help validate that the code is working.

[lilleyse]

The new collection of sandcastle examples is great. I just noticed one issue when picking some of the buildings in 3D Tiles - B3DM Sandcastle example:

[sanjeetsuhag]

@lilleyse There's two problems happening here:

1. Dynamic color of features without a style does not trigger the CPUStylingPipelineStage. That's what happens in the inspector - it sets the feature.color. This is why the picking is only working when a style is set.
2. The "larger" primitives seem to work fine, the smaller ones don't. Still investigating this. The root cause of this was due to the passes not being set correctly when there were both translucent and opaque features in the model.

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The fix was to add a _styleCommandsNeeded dirty flag in ModelFeatureTable that keeps track of the changes in the number of translucent features in the batch texture and if the types of commands needed are changed, it sets the flag, which is read by ModelExperimental, which calls resetDrawCommands in the post render event.

[ptrgags]

@sanjeetsuhag sandcastles are working nicely!

Had a couple last questions for you.

[ptrgags]

@sanjeetsuhag nearly there, just a couple last things

[ptrgags]

changes look good, @lilleyse did you want to take a last look or should I merge?

[lilleyse]

@ptrgags if you're happy you can merge

[ptrgags]

Merged! Thanks @sanjeetsuhag