majikal Posted January 25, 2011 Share Posted January 25, 2011 Hi. Is it possible to motion blur animated displacement? The base geo does not move or deform. tnx Quote Link to comment Share on other sites More sharing options...
pclaes Posted January 25, 2011 Share Posted January 25, 2011 If you have vector motion texture to accompany that animated displacement I'm sure you can add it to the velocity that way. Never done this though. Quote Link to comment Share on other sites More sharing options...
majikal Posted January 25, 2011 Author Share Posted January 25, 2011 oj.. The displacement is antialiased noise. I move it around with offset. I want to achive this: painting-with-polygons without deforming geometry. Quote Link to comment Share on other sites More sharing options...
majikal Posted January 26, 2011 Author Share Posted January 26, 2011 Is there any other way to feed mantra with velocity vectors,than point attr? Quote Link to comment Share on other sites More sharing options...
pclaes Posted January 27, 2011 Share Posted January 27, 2011 Is there any other way to feed mantra with velocity vectors,than point attr? Not that I know of. You almost need to be able to intercept the geometry at the micropolygon level. I have no idea if you can do it. I don't know exactly where the geometry shader call is being made, but it would be after the motionblur. So it does not make sense to modify the velocity inside the shader (I don't think you can). I don't think you need a particular high subdivision level for the point based motionblur to work though. I don't know if there is a way through SOHO to get to the diced geometry. It's a good problem . It would be nice if you could look up the velocity of a point in space through a pointcloud or a vector field at rendertime as you would do with a color (in the shader). But I have not heard anyone do this yet. So sorry, I don't know an easy way to do this. But if you need a blurry edge (that's pretty much what it is, no?), what about using volumes. How about: 1) write out a pointcloud in your shader. This will give you access to a very high density pointcloud that has the displaced information in it. In renderman there is an option that makes sure the backfacing polygons are diced as well. But I don't know if that feature exists in mantra, and you also want an evenly diced surface, not screen space based. There are probably render parameters to do this. 2) You create a low resolution volume (4x4x4) around your mesh and set the density to 1. 3) Inside a volume cloud shader you look up the pointcloud with the displaced information. You use the pointcloud as a mask to indicate where there is density. You can look up the color from the surface as well in the same way. 4) The detail of that volume is defined by the volume steps on your mantra rop. I have no idea of the above, and it would probably quite heavy to compute, but there are examples on the forum that show the above techniques. Especially some of "petz" files have good pointcloud useage in them. I believe one of them was on emitting particles from displaced meshes. Good hunting! Quote Link to comment Share on other sites More sharing options...
majikal Posted January 31, 2011 Author Share Posted January 31, 2011 pclaes thank you for your answer.. I will try that... Quote Link to comment Share on other sites More sharing options...
Gaviteros Posted February 15, 2011 Share Posted February 15, 2011 pclaes thank you for your answer.. I will try that... If you only need overall motion blur and don't need the intense micro-polygon displacement that a shader will give you can do the displacement in the geometry context. If that is animated then motion blur should work. Check out my painting with polygon's post for a hip file that explains the methodology. Quote Link to comment Share on other sites More sharing options...
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