Shrinking grid

[ben_hamburg]

It might be related to the numerical errors bug I?ve posted earlier, but I?m still having problems with a setup, where the grid starts shrinking at a certain point.
I have adaptive grid enabled aswell as "no smaller than initial grid". The setup is still based on the volcano, but I?ve added a Pflow, throwing out big chunks of debris out from the middle of the volcano. I?m guessing it has possibly to do with the speed of the debris being to high or being born from one frame to the next in the middle of the simulation. After a couple of frames the grid. that has been adaptively expanding, now starts shrinking, cutting it off at the borders.
Have you seen this issue before and would increasing the SPF value help to fix this?

I?m not sure I really need it, I have also simulated the debris emitting smoke in a separate simulation and I?ll probably just blend them together or just render them at once, giving the illusion the basic smoke from the volcano and the smoke trails from the debris were connected.

Would still be nice if the Pflow for the debris would have a direct impact on the base simulation for the volcano smoke.

Could this also be achieved via some sort of cascade setup (like the Waterfall example), or does that only work for liquid sims?

[George Barzinski]

Hi,

There is an option in the latest nightly builds called Expand and Don't Shrink (in Grid roll-out menu). Also, you can set additionally an Extra Margin value which would expand the grid a little bit further than the smoke and won't clip it. Check once again the adaptive grid channel and its threshold. And yes, you can make the setup using cascade sims.