shawn_kearney Posted July 6, 2017 Share Posted July 6, 2017 Is there a way to calculate or obtain the degree of energy imposed onto FLIP particles resulting from collision as either a scalar or vector value? Quote Link to comment Share on other sites More sharing options...
KarlRichter Posted July 7, 2017 Share Posted July 7, 2017 If you subtract the velocity of the previous frame from the current frame, that would give you the direction and magnitude of the "force" that affected your sim that frame. Quote Link to comment Share on other sites More sharing options...
shawn_kearney Posted July 7, 2017 Author Share Posted July 7, 2017 Ok. That was kind of my plan. I suppose I could use a POP Collision(?) DOP to isolate RBD- collided flip particles ... haven't used that node for a while.... Quote Link to comment Share on other sites More sharing options...
KarlRichter Posted July 7, 2017 Share Posted July 7, 2017 That would probably work, although I have found the POP collision node to be unreliable with FLIP if your particle count is changing rapidly (like if you have reseed on). You may consider using a sop solver with the "xyz distance" node to make your own collision detection. Quote Link to comment Share on other sites More sharing options...
tricecold Posted July 7, 2017 Share Posted July 7, 2017 you can do this after simulation also drop a wrangle, connect the same cache with a 1 frame offset to second input vector oldspeed = point(1,"v",@id); \\get the previous frame point velocity vector float speed1 = length2(@v); \\ measure current speed float speed2 = length2(oldspeed); \\ measure previous speed f@ratio = abs(speed1/speed2); \\ get the change ratio basically, if the ratio is 1 then speed hasn`t changed and vice versa, or sth like that Quote Link to comment Share on other sites More sharing options...
shawn_kearney Posted July 7, 2017 Author Share Posted July 7, 2017 Another issue is that this would account for all force, not just collisions... Though this might not be a problem. And yeah, i would do it in a SOP solver. I want to take a stab at non-Newtonian fluids that change viscosity with force. Quote Link to comment Share on other sites More sharing options...
KarlRichter Posted July 8, 2017 Share Posted July 8, 2017 Ahh... For non-Newtonian you may want to look at pressure. You can turn the pressure field into a particle attribute by using the "gas field to particle" gas microsolver. Then use that to drive the viscosity or something. See attached for a quick example. pressure.hip 3 Quote Link to comment Share on other sites More sharing options...
shawn_kearney Posted July 8, 2017 Author Share Posted July 8, 2017 (edited) 2 hours ago, KarlRichter said: Ahh... For non-Newtonian you may want to look at pressure. You can turn the pressure field into a particle attribute by using the "gas field to particle" gas microsolver. Then use that to drive the viscosity or something. See attached for a quick example. pressure.hip wait. the what to WHAT? Oh this is going to get fun. I knew that there was something like this, just wasn't sure how to get to it! THANKS. Edited July 8, 2017 by shawn_kearney 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.