Hello all, I'm going through the gas solver tutorials in the SideFX site and I can't seem to figure out why I can't get the geometry(boxes) to deform. When I load in the provided scene: (5.create_gas_solver_gas_nondivergent.hip)

and uncheck the bypass flag for the applydata node, the boxes deform great, but if I recheck the flag and uncheck it again, the deformation is gone. How do I get Houdini to update properly? Thanks
TD

you'll need to resimulate

I set the playback to the start position and hit play. I checked that playback is set to play all frames, but I'm still not getting deformations on the boxes. I attached the file for all to look at. Thanks.

Your Apply Data is disabled, which needs to be on in order to apply the geometrycopy so you have an instance of the incoming geo(since just SOPgeo alone merely points to geo, it doesn't allow you to alter it).

Additionally, your SopGeo DOP is set to Set Always for Time and SOPPath, this means the pop-driven moving boxes will simply be thrown into the DOPnet at each frame, and the effect of the sim on it will be nil. You either need to let the vector field move it(with an initial incoming setting), or do your popnet move. Set those both to default, your initial data will be distorted by the vel.

Now, I'm actually just starting to get into all this(and in fact it's been good for me to debug your hip - thanks! ), so that doesn't mean you can't have an animation and have it affected by forces, I just don't have an answer on the tip of my brain. Someone else might have a thought. Certainly my first thought would be to pull the popnet into DOPs, rather than have it external and unaffected.

Cheers,

J.C.

Thanks for your help JColdrick. Your reply led me to get it working. I set the sopgeo1 - Sop Path to default,and the time to always. Then I went into the geometrycopy1 and set the Default Operation setting to Always. And everything looks great…WooHoo!

/me hits head. Of course, that was it - the copy operation needs to happen every frame. So many switches…so little time…

Cheers,

J.C.