Deborah R. Fowler

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Posted: Oct 28   2013 
Updated: May 3  2015
Update: Oct 23  2022 - this is now provided automatically as an option that you can select with a collision object

Flips collision object Using OpenVDB

Thanks to Jamie German/James Charles for this tip:

In the object to be used as a collision object in your Autodop, go into the geo container and after the dopimport node add a reference object (OUT_VDB in the diagram below). This will not be used in rendering the object, but simply as a reference in the Autodop network. OUT_VDB is a VDB From Polygons Node. Reduce the Voxel size appropriately on this node (say .02).




Note that this was set up for a proxy object that was static. The rendered object was in a separate node. You can also use a proxy object that is animating. Remember that the dopimport is giving you the transformations so you need to put you real object (to be rendered) connected to the dopimport and then reference the proxy object in the dopnetwork as seen below. The proxy is used for the computations but the object rendered needs the transformation information from the dopimport.

Now in the autodop, your Static Object will come in as mode Volume Sample, Division Method By Size and Division Size 0.02 (the value to match the Voxel size). With the Proxy Volume path set to point to the object. See Diagram below.



Sim away - much faster when using complex geometry for collisions with fluids. (Click off Display Geometry and click on Show Collision Guide Geometry. These are under the Collision tab along with the above parameters).