Pyro effects passing through Static object

[Janno_91]

Hi, beginner here. 

 

I have a scene where I want a smoke pyro effect to billow out from under a car bonnet, but have run into a few problems. The mesh is all modelled in maya, exported using Alembic and then imported into Houdini. I've made sure the normals are all correct, the mesh is clean and is acting as a static object. The problem i'm having is any smoke that I produce underneath the 'bonnet' mesh passes right through without being effected. I've tried with both volume based collisions and non, and the problem persists. I've become aware that perhaps the problem is because the mesh is too thin and scaling the mesh up does actually fix it, but i'd prefer to keep the mesh at its current size as it already has camera's set up to it's scale for compositing. 

 

Any ideas? 

 

Appreciate your time.

 

 

[Atom]

As with most sims it is not uncommon to create place holder low res geometry to act as colliders. Remove the low resolution mesh from the scene and replace with your final mesh for rendering.

[Janno_91]

As with most sims it is not uncommon to create place holder low res geometry to act as colliders. Remove the low resolution mesh from the scene and replace with your final mesh for rendering.

 

Thanks Atom. I have actually used this method before, making a proxy mesh that was more suitable for particle collisions. Though, this mesh has small(ish) holes in it that the smoke is meant to pass through, like a vent. I fear that modelling these sections again would make the mesh just as complex as it already is. Is it still recommended to make a placeholder that is in essence, an exact replica of the original?  

[arifakca]

have you tried VDB as proxy volume for your collision geometry.?