The titles should really be how to rotate the orient attribute but spinning particles is more catchy. Rotation can be a tricky beast and when it comes to particles there are a bunch of ways to control their direction, and when you are stacking multiple rotations things can become a little hairy! I suggest using quaternions to control direction because the qmultiply function makes it very simple to modify the current orient.
(more…)houdini
Groups to Attribute with VEX
Today at work I was loading some really heavy geometry into Houdini that needed FX added to it. Its came in from Maya with thousands of primitive groups for different numbered parts of the geometry. If you tried it before you will know that unpacking heavy geometry with a lot of groups is any easy way to fill up your ram. In this cache filling 64GB and the cracking Houdini after filling the swap as well.
(more…)Tutorial: FLIP RBD interaction
Tutorial: FLIP – Rest Pos to Texture
Tutorial: Flip Bottle Fill Part 02 Meshing
Tutorial: Flip Bottle Fill Sim
Quick Tip: The Handy Falloff Sop
Combining the falloff sop with a few groups is a great way to control attributes by distance without having to jump into VEX and VOPs. A lot of sop nodes output groups along with the operations they do so I figure you might as well use them when you have the chance. Here are a few examples of the falloff sop in action.
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