How to use impact data of RBD objects

[magneto]

Hi,

I am just doing simple particle emissions on where the object hits the ground. I used the Add SOP to create a point on the Impact field using the dopfield function:

dopfield("/obj/AutoDopNetwork", "box", "Impacts", "Impacts", 0, "positionx")[/CODE]

Is this the right way to do this kind of stuff? I also want to use the impact normal and velocity but it seems like the normal always show [0,1,0] for Impact.

As for velocity, I tried using the Impulse field but is there a way to get its max value through the sim, so you can map it to a new range like 0 to 5 for example?

Is this the right workflow or am I just doing this too manually that there are higher level methods to do the same thing?

Thanks

[cwhite]

You might find it useful to use the DOP Import Records node to import the impacts into points with point attributes (there's an example file for the node that shows how to set this up, and the SOP Solver automatically sets this up for you as well). That would let you use SOP tools to manipulate the impact data.

[magneto]

Thanks cwhite that's useful. I reckoned it must be the node version of this function. I will check the example. But do you know how to use impact normals and velocities or impulses to control particle emission? This way they would look more realistic

[mawi]

Or you can use the impact analysis workflow. (Shelf RBD Impacts)

Cull of the points in sops with $T>$IMPACTTIME

Then use the pointreplicate SOP and duplicate points from attribute impulse ( be carefull here. You might create ALOT of points)

Might be able to put a file up later tonight...

[magneto]

Thanks mawi, never heard of it before. An example file would be gold

[mawi]

Quick and dirty. Based on a hip I did for active/passive RBDs.

Edit...

And dont look to much at the particle VDB collision.

impacts.hipnc

Edited August 13, 2013 by mawi

[graham]

I think this thing still works

http://houdinitoolbox.com/houdini.php?asset=4

[magneto]

Thanks alot guys.

@mawi: Your example is amazing, Way more detailed than I thought

@graham: I will download it now, I am sure it still works

[slamfunk]

Hey guys been scratching my head on how to use the impact data to trigger the active attribute on or off for mutiple objects within an rbd packed object. Any clues as to how this is possible? Ie a group of spheres all collide with a ground plane and upon impact with the ground each sphere goes from active to passive.

 

I've been thinking of ways to use the parentprimnum attribute (from ImpactAnalysis) in a sop solver for this but I can't seem to find the best way to get this and id to play together to create active values per id..

Edited January 15, 2014 by slamfunk

[slamfunk]

One solution is to match parentprimnum in a attribute copy and copy over active value... Need to increase substeps on dopnet to get an active value switch right on impact!

[rayman]

It is simple.

Put attrWrangle inside sop solver after bullet solver step;

Set Mode to detail;

Put Geometry in first input and impacts in second;

Type this code:

int iter = npoints(1);
for(int i=0; i<iter;i++){
    int impactObjId = point(1,"primnum",i);
    
    setpointattrib(0,"active",impactObjId,0);
}

OR just check the attachment (:

 

EDIT: well you are fast !!! (: (:

DOP_Bullet_RBDPacked_impact_deactivation.hipnc

Edited January 16, 2014 by rayman

[slamfunk]

Awesome thanks rayman.. will check your solution out! Really want to be using the wrangle sops more!!

[Yanana]

Hi, I'm trying to go through the wole RBD sim workflow for the first time. I'm trying to get my debris working now and I have the DOP Import Records method working for importing my impact data, but I'd prefer to get the Impact Analysis method working. The $T>$IMPACTTIME expression doesn't work though and I have no idea what could be wrong. :/ 

[luc255]

Realy cool but how do you transfert particule color to mesh ?

if(@impactobject == @id)
@Cd.r = 1;

[michela]

Any tips for accessing ImpactAnalysis in Dynamics CHOP? I can only seem to get the Impacts/Impacts/impulse field nothing else

Ideally would like to get ImpactAnalysis/Options/Reset Total into a CHOP