ffd on water mesh doesn't affect particles

I have a camera low to the simmed liquid water and I’m deforming some tall waves with an FFD to keep the camera above the surface. It works fine on the liquid mesh but the splashes/foam particles aren’t following the FFD. Is this possible to do?

If not, how could I map on a gradient (greyscale) so that the area near the camera is lower - I’d plug it into the liquid mesh displacment - I’m guessing the particles would follow that deformation. Have also been trying that and can’t seem to deform the mesh in only the Z direction, plus how can I map it with a UV?

Thanks!

Indeed, the particles will follow the displacement of the connected Liquid Simulator.

Maybe you could use a V-Ray distance texture? It produces a grayscale mask around a geometry, so if you add an invisible sphere over the camera, this texture could serve as displacement scaling for the ocean tex.

That’ll be my fallback plan… using displacement takes a long time to render though unfortunately. 12min/frame vs 2min O_o

Is there really no way I can use an FFD or other deformer to affect the splashes/foam? It’s a shame since it works so well on the ocean mesh - just need it working on the drops and then I can get back those great per-frame render times.

Are you using V-Ray 3 or Next? V-Ray Next has optimized the distance tex tremendously (several times faster).

It’s somewhere in out TODO feature list to be able to modify particles with modifiers, but hasn’t had many votes yet. WIll add another one…

Oh wait, if you are using the Phoenix ocean displacement, you could just use ‘displacement fade’ and use a geometry - this will be the same result as using the distance tex.

No this sim doesnt’ use any displacement - it’s too slow to be able to make the delivery. I had to render straight sims as is, without displacment. How soon could the feature be added to modify particles with modifiers? Is it possible?

It is possible, but it’s not coming during the coming few months, sorry.

Roger that - I’ll look into bobbing the camera up and down or pivoting the water mesh. Thanks Svetlin for all your help and suggestions. Much appreciated! Water is looking great!