Dops attractor force

[bandini]

I am trying to accomplish something in DOPS, and I am a bit lost. Hoping for some help or a quick example .hip.

I want to create a simulation where objects are being attracted to another object's points. Each point should have only one object assigned to it. I want to use an RBD point object and bullet as the solver.

I have goal positions assigned to my RBD point object's points, but they do not carry through into DOPS. So, one question would be how can I attach that data to my DOPS objects? The other issue seems to be that data is not read into the vop force (I tried with a rbd fracture object, with attached geo data).

The reason I am using DOPS instead of POPS is that I need particle-particle collision.

Any help would be appreciated. Thanks!

-adam

[sadhu]

Here is one quick file to convey an idea.

Vel vector is created by goal pos minus rbd pos data and applied to rbd obj by rbd state node.

point expression is used to access point pos of an obj (GOAL), dopfield expression is used to access Position data of rbd objects (followers) (Find out the relationship between pt no and objid before using point or dopfield expressions to get the desired output)

You can easily control which points on goal obj followers should follow in different ways using sop tricks. Attached file is just an idea.

dop_goal.hipnc

[bloomendale]

Hi.

Here is example.

As for point rbd dop - it just uses points to extract position to fill in Position data of rbd object. So if you need attributes from SOPs on your geo data in DOPs do it manually.

As for VOP force DOP - it's CVEX shader and you can import attributes from point cloud (import point pos from target object). But as render-time thing i think you can't use "op:/path" syntax in it, only real path to geo file (imho).

3ak_moveToGeoPonts.hipnc

[bandini]

Thanks! I'll check out both examples!

[memu]

Hi.

Here is example.

As for point rbd dop - it just uses points to extract position to fill in Position data of rbd object. So if you need attributes from SOPs on your geo data in DOPs do it manually.

As for VOP force DOP - it's CVEX shader and you can import attributes from point cloud (import point pos from target object). But as render-time thing i think you can't use "op:/path" syntax in it, only real path to geo file (imho).

Hi.

Thank you for putting out an example file! I've also been trying to figure out how to attract DOP object to custom points with no luck:)

Your file works great, but when i add a ground plane the DOP objects start flying everywhere. Do you have any idea to why that is happening?

I want the objects to bounce once or twice and then move to the goal object.

Thanks

[bloomendale]

Hi.

If i remember right i use expressions to pull some info from SOPs to DOPs. And i assume that my OBJID == PT in SOPs (object with OBJID ==0 gets its data from point in SOPs with PT ==0 and so on), but when you add Ground Plane object (static one) its OBJID becomes 0 shifting all cubes' OBJIDs by 1.

So you need to change $OBJID in expressions with $OBJID - 1.

Hope this helps

Edited October 23, 2012 by bloomendale

[memu]

Hi.

If i remember right i use expressions to pull some info from SOPs to DOPs. And i assume that my OBJID == PT in SOPs (object with OBJID ==0 gets its data from point in SOPs with PT ==0 and so on), but when you add Ground Plane object (static one) its OBJID becomes 0 shifting all cubes' OBJIDs by 1.

So you need to change $OBJID i nexpressions with $OBJID - 1.

Hop this helps

That fixed it! Thanks alot:)

[cgstar]

nice!