Justin Keil


About Me

VFX Artist
United States


Recent Forum Posts

Bullet Solver problem: min_activation_impulse and constraints? Oct. 24, 2018, 11:47 p.m.

Hey all,

I have an interesting conundrum Im trying to wrap my head around. I have a suspended fractured object in a scene that needs to stay inactive until it gets hit by a collision object, then behave active as a group once any one of the pieces is hit. I have it working with a combination of the min_activation_impulse and a sop solver–all the sop solver does is sets the entire object to active once one piece is hit. The min activation impulse lets me set the object to static intitially, and then change over to active once there is some sort of impulse that hits the objects.

The issue is now the constraints. The constraints make it so that there is a delay between the recognition of the update by impulse and the result of the solver– its not until the object is hit a couple times that it becomes active, pieces can break, and it can fall overall.

If the constraints are off, the min_impulse activation works instantly. It is only when constraints are on that I get the delay. Is there a workaround for this.

Thank you!

Ive attached a file.


Rotational Constraints for Cloth Sept. 21, 2018, 10:52 a.m.

Hello all,

Is there any way to constrain the rotation of a cloth object as well as its position?

I am attaching three cloth objects to a wire solver-the cloth objects are small and shaped like leaves- a bit rigid form wise. They are being attached to a branch coming off a stem(both simple wires). The wire and cloth objects are each being controlled by their respective solvers, and the relationship between the objects is set to constraint only (on the merge node). For the actual constraints, I am using the cloth stitch constraint (under the hood just a position constrain relationship– with the crucial SBD relationship as well). I am just using the pivot point of the leaf to constrain each leaf to the perspective point on the wire. The solve is actually stable, the clothstitch constraint works really well to constrain the cloth objects to the wire, however this is position only–in fact all the SBD constraint systems seem to be position based only. A traditional rotation anchor is not recognized by the two parties here. Is there a way around this?

Perhaps I could do something on a sop solver level if need be…..

Ive uploaded a file.

Thank you!

Fluid Stream affecting Piece of Cloth _ Fluid Force Issues (SOLVED) May 28, 2018, 3 p.m.

For anyone's edification!

Here is the correct way to set this up–thanks sidefx support!