Scale Growth
Scale growth visual effect created in Houdini using VOPs.
Overview
To become familiar with working with VOPs in Houdini, I created a scale growth effect. I can see the benefits of VOPs over scripting in VEX, especially when effects require some nosie and an art-directable organic quality.
I first use the distance attribute with added noise to drive the growth effect. The growth factor is used to control the pscale of the scales over time, causing them to appear. To give the growth a more organic quality, I also add noise to the normals and a spring effect to give it some jiggle.
Process
The growth region is generated by measuring the distance of each point from two different points placed near the geometry, and using the frame number to drive the srcmax value of the distance measurement. Another option I tried was using a Pyro Source Spread simulation, but found this to be simpler.
I then use an attribute blur to make the transition region smoother and more gradual.
