PRT Volume - Shape Index? Bias Random Radius

Krakatoa for 3ds Max
1

Hello,

I have a PRT Volume that I am using to fill a geometry volume with points, then I’m using Frost to scatter cards onto the points.
I am trying to build a magma mod on top of the PRT volume that will write random values into the radius channel. I realize that I can vary the radius in Frost, but I want mostly small cards with a handful of ‘rogue’ larger cards. The Frost random radius seems to do a linear randomization with equal parts across the spectrum.

I was thinking I could pipe the shape Index into a noise, but the PRT volume’s point do not have a shape index? I’m also unclear on how I would bias the randomness once I get a per point constant and noise working.

Does anyone know how to do this?

Thanks,
Bob Dyce

2

Okay - with some further forum reading and digging around, I’ve found that for a PRT Volume, there is not consistant shape Index, but I can use an input channel ID.

I’m still struggling with how to randomize the radius so that I can get 80% of the points in a random range of say 100 to 200. An the remaining 20% in a random radius from 1000 to 2000.
Any ideas?

B

3

I ended up using a Modulo to make the IDs cycle from 1-10 then a curve to shape how many particles got a large radius vs. a small radius. I’m still curious how someone else might approach this. In the end out flow worked, but it feels pretty janky.

Thanks,
Bob