The Mill - Week 3

Blog post description.


1/14/20243 min read

This week I will continue to explore the transition effect for our Vespa. For the transition effect, I decide to render different layer to do the compositing afterwards.


Peeling Effect:

I use the Vellum Solver to simulate and do the edge fracture to have the piece attribute.


At first, I just use the Solver to drive the gradient attribute from 0 to 1 to control the gradient release pin animation to let the peeling effect gradually.

But I don't want the Peeling Effect flying forever, so I need the 'Attribute' to drive the flying chips when they flying.


I use the Pyro Spread to set the temperature attribute to make the flying chips become smaller when they flying. Set the specific condition for temperature and control the rest length scale attribute by using the POP wrangle.

Using the Temperature Attribute in Pyro Spread to control the gradient attribute I need later.

In the Vellum Solver I use the temperature to control the 'Vellum Constraint stopped'.

To let the flying chips become smaller, I set the condition for restscale by using temperature.

New in Houdini 18: SOPs Pyro Spread

Houdini disintegration animated object using vellum with pyro source spread

In the every popnet, I use the point VOP to control the color and pscale by age and life

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Merge different POP sources with similar values to make some detail of the particles.

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In order to let the particle source be random. Every 'Particle Source' I had set the noise on scatter point. Also, using the point Vop to animate(offset) the noise. After the noise I set, I just use delete by expression to remove the black point.

Moreover, sometime I will set the simple condition expression for the 'Impulse Activation'.

Using Pyro to set the inherited velocity, so it will have more realistic particles.

Make the particle for the pyro source, and then use simple vex to remove additional particle.


I use the reference copy and then invert transformation for the Pyro Simulation.

POP Solver

Using this vex could let the particle have the bouncing effect along the point source.

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In order to visualize the velocity in particle, I use popcolor to achieve it.

Connection for the old Vespa to new Vespa

I use simple Vex and add some noise to the Alpha.

I set the attribute noise attribute (noise), and then make the ramp for the Alpha.

I also set the attribute blur for the position.