How to use an SDF volume for POP Collision Detect DOP?

[magneto]

Hi,

I am trying to figure out how to use an SDF volume for POP Collision Detect DOP, but I can't get it to work. SOP collision is easy but I want to use an SDF volume. I set the Collision Target to DOP Objects and referenced my new obj0 (Empty Object) with a SOP Scalar Field DOP that points to my SDF volume but it doesn't work.

Either I am using the wrong syntax in the DOP Objects field or this option doesn't support an SDF. If it doesn't support SDF, then what's the right way to do this for particles?

Thanks

[anim]

just create RBD or just Static RBD and use your SDF as a Proxy Volume for volume based collisions and mode to Volume sample, no need for specifying geometry for object itself or resolution for SDF as it will not be recomputed therefore SDF from sops will be used as is

look at the file

apart from that note that any RBD with Volume based collisions will use volume representation with POP collisions

EDIT:and you can as well just use Collide Relationship as your collision target instead of specifying DOP object directly

sdf_rbd_collision_detect.hip

Edited December 9, 2013 by anim

[magneto]

Thanks anim, your method helped me greatly. So if I am not wrong, then do you only use SOP Scalar Field DOP when using micro solvers with your SDF volumes?

With your RBD solution, now I can even have them animated much easily.

[anim]

correct, to attach SDF as dop data you can just use SOP Scalar Field DOP and then you are able to do whatever you want with that so any microsolver that uses volume/SDF field will be able to access/modify it correctly for your own calculations

other option is to access it directly from SOPs from within various solvers like Gas Field VOP, Geometry VOP, ...

however, if you want to use it as a collision volume which gets recognized directly by RBDs and some other solvers like in the example, you need to use it in similar fashion as inside RBD object so as a SDF Representation DOP node (data named Volume) attached to Geometry data and with optional SOP Geometry attached to it which can feed SDF from sops directly, but it's much simpler to just place RBD Static Object as in the example so you get this setup for free