Aaron_ Posted July 16, 2013 Share Posted July 16, 2013 Hi folks. Can anyone explain how to pre fracture geometry with VDB like this one: https://vimeo.com/70409265 Quote Link to comment Share on other sites More sharing options...
Scratch Posted July 16, 2013 Share Posted July 16, 2013 (edited) Dont know how to do that with VDB, but with voronoi you would model the wood-stick like this ----------------------- then scale it using the transform node until it looks like this ------- perform the fracture and scale it back up to its original size. Doing so, you also scale the fracture-pattern and you get the desired wood-splinter look. I found this technique in the voronoi fracture cours over at digital tutors. Its really nice, and worth checking out! Maybe you can adapt that technique somehow to work with VDB. I am afraid i haven't explored VDB enough to be of more help. I'd do it with a regular voronoi fracture node and convert the result to vdb if it has to be vdb using a vdb from polygon sop. Hope it helps a bit anyway! Edited July 16, 2013 by Scratch 1 Quote Link to comment Share on other sites More sharing options...
edward Posted July 17, 2013 Share Posted July 17, 2013 The VDB Fracture SOP works by you giving it some "cutter" geometry (closed polygon surfaces) that it uses to fracture your input geometry (converted into a VDB SDF). More details here: http://www.sidefx.com/docs/houdini12.5/nodes/sop/vdbfracture I think the trick with the above video is how you come up with some convincing "cutter" geometry, which can make use of Houdini's proceduralism. Quote Link to comment Share on other sites More sharing options...
JonathanGranskg Posted July 17, 2013 Share Posted July 17, 2013 I tried the vdbfracture a few weeks back, but I was having some trouble with a few things. A basic setup ended up with having pieces floating (connected to other settled pieces) and doing a little fixing up using a connectivity sop helped a bit, but I was still having some trouble with it. If anyone has any tips for fixing these problems, they'd be appreciated. First file shows the problem and the second one shows my half-assed connectivity sop fix. The connectivity sop simulation still has three primitives floating in the air, otherwise it works fairly well. The scene is very rough, but I think you get the idea. Reading the help documents on the vdb fracture will get you a long way. vdbFractureTest.hipnc vdbFractureTest_maybeFix.hipnc Quote Link to comment Share on other sites More sharing options...
j00ey Posted July 18, 2013 Share Posted July 18, 2013 Hi Jonathan I'm just exploring some vdb stuff too. I looked at your scene, it seems you can replace the 3 connectivity and attribute create / attribute nodes with an assemble. The way the pieces falls changes when you do this and I don't know why... Also I made a version myself just to replicate the procedure and my geometry doesn't break apart until it hits the groundplane. I looked at your settings and I can't see what it is that's making the difference. My scene file attached in case you could have a quick look for me.. Thanks vdbFracture.hipnc Quote Link to comment Share on other sites More sharing options...
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