Houdini Particle Morphing Effects


Houdini Particle Morphing Effects

I just created a new tutorial for CMIVFX about doing particle morphing effects in Houdini.  I think it is a great collection of useful information and shows how to get some nice, natural motion with your particles.  If you want to improve your particle simulations and overall understanding of Houdini, I highly recommend watching this tutorial.

Houdini – Delayed Load Test

Just a quick test of the delayed load technique presented in Peter Quint’s tutorials for rendering millions of particles.

This render is about 1.5 million particles. Took 50 minutes to render. About 15 minutes to sim and cache to disk. Ran a wedge of the emission seed seven times.

Houdini Particle Morph Example

These movies are made with a setup I created for doing particle morphing effects in Houdini. The initial idea for the setup is from Peter Claes’ technical dvd, but it has been greatly expanded to take color and normals into account. It also allows the user to specify attributes to use to blend between color/motion/normals (such as distance to target, age of particle, length of time in group, etc), which are hooked up to ramps for a great deal of control. I may post a screen capture of how the OTL works soon.

Houdini Particle Aura

This is a quick little demo and explanation of a setup I created for doing a particle aura.  Particles are emitted based on the object’s normal direction from the camera.

This is a screenshot of the VOP network that is doing the magic.  Camera position is imported (into the particles’ object space).  Normalized vectors are determined from each object point to the camera.  Then the dot product of the object normals and direction vector are taken.  If the dot product == 0, then the normals are perpendicular to the camera. Otherwise they are pointing at the camera.  The range varies between -1 and 1, which is then made useful for remapping by taking the absolute value and reversing the grad values so the user interface makes a little more sense.

The “emit” point attribute is promoted to a prim attribute after the vop, allowing it to be used as a particle birth attribute.