Shadows for 3D Tiles

[lilleyse]

For #2594

I still have to figure out why the translucent commands are not casting shadows. They seem to get to the step of casting into the shadow map but the shadow map is empty... I'll figure it out soon.

[pjcozzi]

Also for #3241.

[pjcozzi]

I still have to figure out why the translucent commands are not casting shadows

They are probably not writing depth. This is also an issue for picking. Update the TODO or fix it now if you want.

See https://github.com/AnalyticalGraphicsInc/cesium/blob/3d-tiles/Source/Scene/Cesium3DTileBatchTableResources.js#L416

[lilleyse]

Ah.. that must be it. I'll try to fix the TODO as part of this PR.

[pjcozzi]

Do you get this test failure in this branch?

Scene/ShadowMap shadows are disabled during the pick pass
TypeError: Cannot read property 'receiveCommand' of undefined
TypeError: Cannot read property 'receiveCommand' of undefined
    at executeCommand (http://localhost:8080/Source/Scene/Scene.js:1495:44)
    at executeTranslucentCommandsSortedMRT (http://localhost:8080/Source/Scene/OIT.js:567:13)
    at OIT.executeCommands (http://localhost:8080/Source/Scene/OIT.js:575:13)
    at scene._executeOITFunction (http://localhost:8080/Source/Scene/Scene.js:1685:32)
    at executeCommands (http://localhost:8080/Source/Scene/Scene.js:1786:13)
    at executeCommandsInViewport (http://localhost:8080/Source/Scene/Scene.js:2104:9)
    at updateAndExecuteCommands (http://localhost:8080/Source/Scene/Scene.js:1963:17)
    at render (http://localhost:8080/Source/Scene/Scene.js:2369:9)
    at Scene.render (http://localhost:8080/Source/Scene/Scene.js:2407:13)
    at render (http://localhost:8080/Specs/Scene/ShadowMapSpec.js:352:15)

[pjcozzi]

Do you get this in the 3D Tiles Sandcastle example? Clean build, cleared cache, forced reload.

[lilleyse]

I'm not seeing either issue on Chrome, even after hard reload. But I am seeing it on Firefox and it reminds me of what used to happen. I do have a fix for it, but it's more of a band-aid.

[pjcozzi]

I do have a fix for it, but it's more of a band-aid.

Push it and I'll see if I have any other ideas.

[pjcozzi]

Did you mean to commit these changes?

[lilleyse]

Yes, because it helps to see real use cases inside development/Shadows.html. But I can see how this is a problem. I'll switch to using the test 3D Tiles sets we have and change to using Seattle/etc locally.

[pjcozzi]

Does the 3D Tileset primitive need any changes to its update function so the shadow map pass doesn't impact the load queue or cache?

[lilleyse]

Updated with the "fix".

[lilleyse]

Does the 3D Tileset primitive need any changes to its update function so the shadow map pass doesn't impact the load queue or cache?

I don't think so. It will just use whatever commands are pushed from the render pass.

[lilleyse]

I fixed the issue with translucent buildings not casting into the shadow map. It was not related to the depth writing, instead it was caused by the pass == translucent checks in the batching shader. I needed to set the pass right before casting in order to fix that problem. I left the picking depth TODO in for now since it's unrelated.

Also in regards to the crashes we were seeing, the reason behind that is OIT commands, being derived from the original commands, do not have derived commands themselves, which is why we were seeing problems with derivedCommands.shadows being undefined. But since the OIT commands have shadows code built in, it all works out. The fix I made is actually fine.

[lilleyse]

When this is ready I'm going to merge the Scene.js changes into master as well.

[pjcozzi]

Can you fix the JSHint warnings even if they are not related to this PR? https://travis-ci.org/AnalyticalGraphicsInc/cesium/builds/135932620

[pjcozzi]

Can you add a comment here like the GiHub comment since the overall order of operations may be non-obvious to those new to the code?

[pjcozzi]

Merging, just make those other changes in the 3d-tiles branch.