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[SOLVED]Tree motion is jittery when far from the world origin.


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Hi, we have observed that in a double precision build if you have a tree far from the origin, the motion from wind is not smooth, the tree "jumps" between different animation points looking very strange.

 

This is easy to replicate without a test case scene.

 

  1. load a double precision build of the editor
  2. load a tree node file (i used birch2)
  3. observe all looks OK
  4. move the tree node to a far away world location, i used 500000,300000,0
  5. observe that the tree motion from wind is now very stilted and jittery.

Most of our simulator worlds are built in real world coordinates making this a huge show stopper.

Thanks

 

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Hi frustum, can you give some hint on the cause of the exaxt problem and how you solved it ? I would guess some float precision issue on wind animation offset based on xyz position. BTW just as a question: will ObjectGrass show the same issue ?

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ObjectGrass is free of this issue because it doesn't use world coordinates as a source for noise calculations.
Shader noise for trees was based on world position. Absolute values of noise were huge as result shader floating point precision wasn't sufficient.
I have added a "virtual origin" for all shader world position calculations. This origin will solve all precision errors.

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Hi, will this be in the next sdk release or an interim build? we are planning to update our software to the latest SDK version next week and would rather hold off if it will be in another SDK.

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