Fix pickPosition called after sampleHeight

[lilleyse]

Fixes #7111

If the previous pass was a sampleHeight call the state would be wrong for the pickPosition call. This resets frameState and uniformState in pickPosition.

Specifically SceneTransforms.drawingBufferToWgs84Coordinates requires log depth and inverse view projection to be correct.

Slightly modified demo as #711 I used for testing: localhost:8080 link

• Still need to do more testing and write a unit test.
• I wonder now if pickTranslucentDepth really requires a manual scene.render call. It should be able to do something similar to this I think.
• CHANGES.md

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[lilleyse]

Updated. @bagnell could you review?

[lilleyse]

Also @ggetz can you test this in the demo where you first ran into this problem?

[ggetz]

I'm still having problems picking when zoomed in close to the entity in this example

When the camera is close to the entity, it doesn't work at all. At a medium zoom level, it works at positions that are far enough from the camera. It works fine when the camera is zoomed out far enough. Could it be a picking frustum issue?

[lilleyse]

That might be a different problem related to the label offsets. I see it too when clampToHeight isn't called. With a few label tweaks it seems to work better:

Modified example

[ggetz]

@lilleyse Got it. I'm not running into any other picking problems here, and this also resolves the issue with the original tileset I saw. Thanks!

[lilleyse]

Merged in master. @bagnell could you review?