Activating vellum grains part 1 in Houdini | FREE TUTORIAL

Lets look into how we will control the places that grains become active for vellum. There are multiple ways of achieving this result, but id like to show you how you can utilize another geometry object to transfer color and based on this color, activate the grains.
Download houdini project:
drive.google.c...
More tutorials:
www.rmafire.co...

[@AshleyGlover]

I have an animated sphere which grow, however for some reason Vellum solver only uses the first intial selection, any way to get over this and use the animated colour of the sphere?

[@tizianoleonardi4696]

same problem here...

[@kalashjaiswal4949]

too good

[@RMAFIRE]

Thanks!

[@rendered_useless2093]

hello the vex @mass = @Cd.r; does not work to activate grains please help. In my instance everything is active not just red bits

[@aeko]

That's because your grains don't have zero mass. At 2:35 he uses a color node to make the grain black (0). Then transferring the black (0) to mass would equal zero mass. Vellum grains with mass of 0 won't move.