Nando Posted April 7, 2014 Share Posted April 7, 2014 hi all ! I am sparring my time in learning alot with Collisions and RBD sim, with the new h13. Now wat i am trying to achieve is , i have an animated character which eventually ramms into a pillar, and the pillar cracks , falls down, i have animated it, cached it, brought into Houdini as alembic file and ropd it again.. all good. but when i add that as an deforming rbd object and let it collide with the pillar i m loosing my brain there.. the problems are, its a fractured pillar and brought in as packed geo, if the gravity is on, the pillar just crumbles all the way down ... and another one is, its a huge character with lots of force in action. i cant get that as it hits, the pillar, i have attached a file and a screenshots of wat i am trying to say! take a look at it and shed some light on wat mistake i am committing in here the roped animation is also attached as a cheap way,i am just turning on gravity on a certain frame , where the character comes closer to the pillar, u can see that in the play blast.. i know i am wrong but i m still learning cheers test_1.hip untitled.mov cache_anim.zip Quote Link to comment Share on other sites More sharing options...
Netvudu Posted April 7, 2014 Share Posted April 7, 2014 (edited) I wanted to help, but you seemed to cache your alembic cache as a packed geometry, so I just get one point instead of the cached animation. Generally, you should find suspicious 26 kb as a file size for 25 frames Edited April 7, 2014 by Netvudu Quote Link to comment Share on other sites More sharing options...
Nando Posted April 7, 2014 Author Share Posted April 7, 2014 (edited) it just works for me, i am not sure wats the mistake... my apologies.. anyways i am adding in the alembic file in here thanks alot now i get wat u told me, i loaded the alembic as houdini geo and i get all the points now! alembic.zip Edited April 8, 2014 by Nando Quote Link to comment Share on other sites More sharing options...
whodini Posted April 7, 2014 Share Posted April 7, 2014 (edited) one thing you could do is use the active value dop node to set the pieces to active or passive. You would want to set it up so that if your character comes close to the pillar (ex. 0.1 units close) it will make the nearest prefracture active. You can check out a hip file I posted here for an idea of how it works: http://forums.odforce.net/topic/19860-rbd-fracture-control-example-file/ Edited April 7, 2014 by rhussain Quote Link to comment Share on other sites More sharing options...
Nando Posted April 8, 2014 Author Share Posted April 8, 2014 HI Rhussain first a big thanks for u share, and the amount of information u put inside the File .. couple of doubts as i have undergone, in the File.. ch(opcreator(".")+"/startframe") u added this in the creation frame of rbd fractured object inside dop..?? why ?? wat does it do actually ?? in the active value dop, i see u bring in the attribute u created its totally cool, one doubt is , this does not work for packed primitives, because there is no "objid" in packed geo ?? any solution on that! Thanks Quote Link to comment Share on other sites More sharing options...
whodini Posted April 8, 2014 Share Posted April 8, 2014 HI Rhussain first a big thanks for u share, and the amount of information u put inside the File .. couple of doubts as i have undergone, in the File.. ch(opcreator(".")+"/startframe") u added this in the creation frame of rbd fractured object inside dop..?? why ?? wat does it do actually ?? in the active value dop, i see u bring in the attribute u created its totally cool, one doubt is , this does not work for packed primitives, because there is no "objid" in packed geo ?? any solution on that! Thanks I'm glad the file was able to help you out a bit. The ch(opcreator(".")+"/startframe") expression is something set by default on the rbd fractured object when you create it in a dopnet. I beleive it's linked to the start frame parameter up a level on the dopnetwork it's contained. As for packed geometry, I realize this wont exactly work because the rbd packed object treats all the pieces as one object, hence $OBJID wont work correctly. Let me dig around and see if I can get this working with packed geo. Sorry about that. Quote Link to comment Share on other sites More sharing options...
whodini Posted April 8, 2014 Share Posted April 8, 2014 alright I have a hip file for you using rbd packed to control the activation of pieces. rbd_packed_controlled_fracture.hip Quote Link to comment Share on other sites More sharing options...
Netvudu Posted April 8, 2014 Share Posted April 8, 2014 Aaaand more help on the way. Here is your very own scene, tweaked and fixed. I also added comments everywhere I added or removed nodes. I think you will like it. Just be sure you point your cache to the correct place for the character. Basically, you want to adapt your scene scale to work comfortably and then you should both create active/pasive pieces with attributes. You could animate those attributes as Ryan did on his last file, but for this case it´s just simpler to just create a glue network with a low glue value so that gravity doesn´t move pieces, but the character does. I hope it helps. test_1_fixed.hipnc Quote Link to comment Share on other sites More sharing options...
Nando Posted April 8, 2014 Author Share Posted April 8, 2014 (edited) Thank alot Netvudu and rhussain for the help Files ! defnetley did learn alot.. to netvudu those attribute creates in the pillar as active and passive is it similar to active value inside dop ?? and i still dont get enough velocity transferig from the character to the pillar! so i did compute velocity with the trial sop but still no luck any other suggestions for that Just out of my curiosity, is it possible to break the constrain network, with a wrangle sop. say, if the force is > than certain value it breaks ?? can this be done ?? i ll post an update soon Edited April 8, 2014 by Nando Quote Link to comment Share on other sites More sharing options...
Netvudu Posted April 8, 2014 Share Posted April 8, 2014 Those attributes are similar to the active value in DOP but much easier to assign since you are adding it to points in SOP. Regarding the velocity, there are two quick ways of making the pieces go farther. The first one is simply raising the bounce of the character collision and lowering the density of the tube pieces (you´ll have to chage the glue network strength again). The second way, which is maybe more interesting is to add a SOP Solver and raise the velocity from a Point SOP and tell it $VX*1.4, $VY*1.4, $VZ*1.4 for instance, or with a VOPSOP inside the SOP Solver. Just be sure to use a switch for this so that it only affects for a few frames. Otherwise you will get a weird behaviour after a while. As for your wrangle SOP question, I´m not sure, but it sounds a bad idea regarding performance. If you tell the Glue Network to check to Network SOP every frame you already loose some performance, and your suggestion would have to be added on a SOP solver, which would make it even slower....but it´s an interesting idea...for someone else to try Quote Link to comment Share on other sites More sharing options...
anim Posted April 9, 2014 Share Posted April 9, 2014 (edited) don't convert the object to volume, Bullet is not using SDF for collisions anyway, so keep it as geometry and everything will be faster, you can Bullet/Geometry Representation to Concave for more precise collision shape if you need to to your velocity inheritance problem: you may want to update houdini if you are using older build than 13.0.348 Monday, March 10, 2014 Houdini 13.0.348: Fixed a bug in the Bullet Solver that prevented collisions with kinematic objects from respecting the kinematic object's velocity. Edited April 9, 2014 by anim Quote Link to comment Share on other sites More sharing options...
Netvudu Posted April 9, 2014 Share Posted April 9, 2014 ouch....Tomas is right. Bullet doesn´t use volumes at all. Quote Link to comment Share on other sites More sharing options...
Nando Posted April 9, 2014 Author Share Posted April 9, 2014 yup, that did chage alot, in speed and Behaviour, i have a couple of results and working more better with them. here are some, i owe u all a big thanks 01.mov 02.mov 03.mov Quote Link to comment Share on other sites More sharing options...
ekenryd Posted May 12, 2014 Share Posted May 12, 2014 don't convert the object to volume, Bullet is not using SDF for collisions anyway, so keep it as geometry and everything will be faster, you can Bullet/Geometry Representation to Concave for more precise collision shape if you need to to your velocity inheritance problem: you may want to update houdini if you are using older build than 13.0.348 Out of curiosity, what is wrong in the earlier versions? Quote Link to comment Share on other sites More sharing options...
Netvudu Posted May 12, 2014 Share Posted May 12, 2014 (edited) some earlier builds were not taking into account the speed of static-animated (a.k.a kinematic) objects Edited May 12, 2014 by Netvudu Quote Link to comment Share on other sites More sharing options...
ekenryd Posted May 13, 2014 Share Posted May 13, 2014 Ok, thanks. Quote Link to comment Share on other sites More sharing options...
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