zdimaria Posted October 30, 2011 Share Posted October 30, 2011 I have an RBD Fractured Object, which has changing point velocities. I am trying to use Inherit Velocity from Point Velocity. On the first frame, everything works as expected, but at frame 2, it doesnt. I feel like its because the initial state velocity is just that, explicitly a first timestep velocity. I am new to DOPs and am having a hard time figuring out how to achieve this. Any help would be greatly appreciated. Zak velocity.hipnc Quote Link to comment Share on other sites More sharing options...
loudsubs Posted October 30, 2011 Share Posted October 30, 2011 yea, Im pretty sure the inherit point vel option is only for initial state. You could use an rbd state node with a point expression in the vel sections. set it to "set always" so it evaluates at each time step, and grab the vel attribute value from SOPs. Quote Link to comment Share on other sites More sharing options...
zdimaria Posted October 30, 2011 Author Share Posted October 30, 2011 yea, Im pretty sure the inherit point vel option is only for initial state. You could use an rbd state node with a point expression in the vel sections. set it to "set always" so it evaluates at each time step, and grab the vel attribute value from SOPs. Thank you, the RBD State node worked perfectly. Quote Link to comment Share on other sites More sharing options...
duanxiaozhi Posted November 8, 2011 Share Posted November 8, 2011 I know it is a stupid question,but could you guys talk more about the point expression? If I use point("/obj/geo1/point3",$OBJID-1,"vx",0) in RBD State,It does not work.I really confuse how to get the point number. Quote Link to comment Share on other sites More sharing options...
sadhu Posted November 8, 2011 Share Posted November 8, 2011 (edited) turn on inherit vel from point vel and set it to set always or Use of prim expression to get the result. inherit_vel_from_point_vel.hipnc Edited November 8, 2011 by sorry Quote Link to comment Share on other sites More sharing options...
loudsubs Posted November 8, 2011 Share Posted November 8, 2011 (edited) instead of the $OBJ-1, just pick a point number, ie: 1. The point expression will get the velocity data from that one point. Also, dont put "vx" just put "v". The number at the end of the expression says if its x, y, or z using 0, 1, or 2. point("../geo1", 1, "v", 0) Havent tried this, but I think you can could use an attribute promote SOP to promote the v attribute from point to detail level as an average. Then use the detail expression to call that into DOPs which will be the average vel of all the points, instead of just a single point. Edited November 8, 2011 by Loudsubs Quote Link to comment Share on other sites More sharing options...
duanxiaozhi Posted November 9, 2011 Share Posted November 9, 2011 Thank you sorry and Loudsubs! This really helped me. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.