3ds max viewport gets very slow during sim

[cb LLC]

Hi For some reason you can barely move around viewport during simulation even with low res grid and preview of smoke disabled. I remember old phoenix never did this. I ma using 2018.4 max and latest nightly built CPU usage is only 20% i9

[Svetlin.Nikolov]

Do you have a lot of scene nodes interacting with the simulator? E.g. a lot of geometry, particles, or forces? Is it a fire/smoke or a liquid simulation and also, is it resimulation, or regular sim?

[cb LLC]

Do you have a lot of scene nodes interacting with the simulator? E.g. a lot of geometry, particles, or forces? Is it a fire/smoke or a liquid simulation and also, is it resimulation, or regular sim?

Hi it is a simulation of hot air balloon (500k polys) and fire. No nodes. The hot air balloon and Phoenix were isolated during simulation. And even when phoenix is not selected viewport becomes unusable

[Svetlin.Nikolov]

Maybe you should send the scene over so we can profile it, or you could manually start removing stuff from the scene and running the simulation until you find which node causes the slowdown.