Forums Technical Discussion Agent unpacking for the purpose of extracting their skeletal animations?

Agent unpacking for the purpose of extracting their skeletal animations?

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mackerBaehr
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Hello

I want to be able to extract animations out of individual agents simulated in a crowd-setup. How can this be done? If I use an unpack on the crowd-sim I can see some bonecapture info but nothing which I seem to be able to (re-)use. Preferably I would want to write out the unpacked agent in a fbx file with bones, skins and animation.

Thank you
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cwhite
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Depending on the format you want, you could use either the Agent CHOP or the various VEX/Python functions for accessing an agent's joint transforms.
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doctorbob
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you don't need to unpack agents to access their bones. there's a few vex functions for looking at their animation.

for example, this will make a single point with a transform from an agent bone called “r_wrist_01”:
// extract a named bone transform from agents
p@orient = 0;
i@agentId = @ptnum;
s@boneName = 'None';

//get agents rig transforms and names
matrix agent_transforms[] = agentworldtransforms(0, @ptnum);
string agent_transform_names[] = agenttransformnames(0, @ptnum);

//get agent transform
matrix agent_xform = primintrinsic(0, 'packedfulltransform', @ptnum);

string bone = "r_wrist_01";
int idx = agentrigfind(0, @primnum, bone);
if (idx >= 0) {
  matrix boneMat = agentworldtransform(0, @primnum, idx);

  //get pos
  vector pos = {0,0,0} * boneMat;

  //add point at joint position + add agent xform
  int virtual_pointnum = addpoint(0 , pos *=agent_xform);

  //get orient + add agent xform
  matrix3 rotmat = polardecomp(matrix3(boneMat*agent_xform));
  vector4 qrot = quaternion(rotmat);

  int set_bonename = setpointattrib(0,'boneName', virtual_pointnum , bone);
  int set_orient = setpointattrib(0,'orient', virtual_pointnum , qrot);
  int set_charId = setpointattrib(0,'agentId', virtual_pointnum , @ptnum);


}
removepoint(0, @ptnum);

you get the general idea. extrapolate to multiple bones, use python HOM, whatever.

cheers,
chrisg
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mackerBaehr
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Thank you both. It gives me a general idea indeed.
In your case, DoctorBob, would that be a pointwrangle applied after the ‘crowd_sim_import’? To extract their data as points with transforms, including orients sounds interesting to me.
Edited by mackerBaehr - Aug. 2, 2018 03:34:46
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mackerBaehr
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Update: It seems to work indeed as guessed: pointwrangle after ‘crowd_sim_import’. Fascinating!
A follow up question, trying to insert multiple bone-names in the vex code generates immediately errors (to the Gods of VEX; i am learning). How can this be done? A single wrangle per bone sounds a bit tedious. Could these bone-names be queried automatically and applied afterwards to the newly created point as attribute?

In Python I can't do nothing, complete and utter noobness. Though once more comfortable with VEX it is on my list
Edited by mackerBaehr - Aug. 2, 2018 03:59:54
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