Multisolver help!

[rich_lord]

I`m trying to make some wire objects scale up in size as they simulate, to give the appearance that they are growing.

I thought I could use a multiSolver with a wiresolver and a sopsolver - the wire solver to sim the wire, and the sopsolver to slightly scale them up each frame.

I never get the results I expect out of the multisolver with sopsolver combination though. In this case, the wire is scaling up for some frames, then just stops. I`d expect it to continue to scale the wire forever.

Any tips on how to set this up, and what im misunderstanding about the multisolver?

Also - to illustrate something else that often happens to me with the multisolver - if I set the transform inside the sopsolver to a scale of 2, rather than the scale of 1.1 that the file has, it doesn't start working until several frames into the simulation. Any idea why this setup might produce a delayed start time? This happens to me all the time using the sopsolver, and also in the new solver node when I'm in sops.

Thanks!

scaleWireObjects.hipnc

[anim]

you need to understand concept of wire simulation first

basically it stores source geometry as RestGeometry, this is a reference for edge lengths and angles

then Geometry is actually simulated one which gets compared to RestGeometry during simulation and appropriate forces are applied based on stiffness etc to force it to return to rest

1. so first of all you don't need multisolver to make your wire grow while simulating

just, animate your source wire in SOPs, and then check Use Deforming Geometry on wire object to allow it to update RestGeometry and therefore wire sim will naturally try to match that state based on your settings

2. if you want to use multisolver, you need to modify RestGeometry instead of Geometry and Use Deforming Geometry should be unchecked.

since what you are doing now is updating Geometry (scaling up) so the difference between Geometry and RestGeometry is becoming larger and so are the forces which force it to return until you reach the point where it appears to stop because the forces are equal with your scaling force

here are both methods

PS: I didn't have the problem with delayed start in your file

scaleWireObjects_updatingRestFromSOPs.hipnc

scaleWireObjects_usingMultisolver.hipnc

Edited January 6, 2013 by anim

[rich_lord]

This is great - I knew about the useDeforming Geometry on RDB objects, bit totaly missed it on the wire solver. Thanks for the detailed explainations too - really useful.

Thanks anim!