Hi!
I tried using a grid as collision object for my particles, but some particles just fall through. I wanted to create my own ground plane and I just imitated the network of the groundplane when it's created by shelf. Still, some particles just fly through. What am I doing wrong? I attached my scene file, would be glad if somebody could help me.

Kind regards,


Phong

There's a few notes about this behaviour. First of all, you are using non-volume collisions on your slanted grid which are somewhat unreliable - it is preferable (and quicker) to use the volume based collision model. Personally, I would extrude the grid just a tad bit, giving it some volume. Then, turn on “Use Volume Based Collision Detection” on the grid's RBD object. Also temporarily turn on “Show collision guide geometry”, and set mode to “ray intersect”. Tweak the divisions until the collision guide roughly represents your grid.

The second part is this: since you are colliding a particle fluid directly against the grid mesh, and then turning it into a mesh with a certain thickness, the fluid mesh is going to stick through the collision grid, simply because the collision was measured at a point, but the mesh hulls are at a different point - at a distance from the fluid particle. Two ways to deal with this: the “correct way” is to set the “Volume Offset” on the particlefluid DOP's collision tab to the radius of the mesh around the particle (0.5 works in your example). The other way is to use the particle fluid surface's “collision volumes” tab to subtract the grid from your fluid mesh.

cheers,
Abdelkareem