MENOZ Posted November 17, 2010 Share Posted November 17, 2010 hi, Im making some tests with dops. I'm activating objects using an animated attribute in sop. I noticed that when objects are activated and bounce on inactive objects the bounce is very high, causing instability and strange behaviours. Using a simple scene with an inactive rbd plane and a active sphere the problem doesn't show up. in the video it shoud be clear.. briks.mov Quote Link to comment Share on other sites More sharing options...
Macha Posted November 18, 2010 Share Posted November 18, 2010 Could it be that the inactive objects act as perfect springs with no energy loss? How about applying a drag force, perhaps only for a group? Quote Link to comment Share on other sites More sharing options...
MENOZ Posted November 21, 2010 Author Share Posted November 21, 2010 (edited) Could it be that the inactive objects act as perfect springs with no energy loss? How about applying a drag force, perhaps only for a group? well, yes, it seems so. You suggest to add a drag force only to those object that bounces on inactive objects? I will try to use a switch solver instead of drive the activation. could this be a bug? EDIT: even switching the solver brtween static and RBD tha behaviour is the same. Edited November 21, 2010 by MENOZ Quote Link to comment Share on other sites More sharing options...
MENOZ Posted November 21, 2010 Author Share Posted November 21, 2010 this is an example file that shows the problem.. rbdBounce.hipnc Quote Link to comment Share on other sites More sharing options...
Macha Posted November 22, 2010 Share Posted November 22, 2010 How about you just reduce the force of your initial state. To me it looks like those jumps are just a result of those values, no? Quote Link to comment Share on other sites More sharing options...
MENOZ Posted November 22, 2010 Author Share Posted November 22, 2010 How about you just reduce the force of your initial state. To me it looks like those jumps are just a result of those values, no? No, I set the initial velocity so the active object can jump on the inactive. if you let the simulation go for a while, you will see that the pieces never stop to bounce over the inactive pieces. does it is the case to sens the hip file to sidefx? It seems a bug.. Quote Link to comment Share on other sites More sharing options...
Macha Posted November 22, 2010 Share Posted November 22, 2010 (edited) Hm, I don't really know the answer to this...sorry. If you can reduce the problem to a minimal amount of nodes and expressions, perhaps that helps. At the moment it is a little hard to figure out which bits are superfluous in isolating the problem. Edited November 22, 2010 by Macha Quote Link to comment Share on other sites More sharing options...
MENOZ Posted November 22, 2010 Author Share Posted November 22, 2010 (edited) ok, got response from sidefx. the problem is that I initialize velocity values, and since the object is inactive it's never solved, and those values remains always the same. great support. rbdBounce.hipnc Edited November 23, 2010 by MENOZ Quote Link to comment Share on other sites More sharing options...
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