magneto Posted March 31, 2014 Share Posted March 31, 2014 Hi, In the old POPs, the Collision POP had a collision event where you could use it with popevent expression in another POP to activate emitting particles on another surface. But with the new POPs, the POP Collision only has a group. I tried using npointsgroup expression with my collision group in a POP Source, but it doesn't work. Basically I want to spawn new particles on the surface which the particles collide with. But I am not sure how to trigger emission based on collision? Thanks Quote Link to comment Share on other sites More sharing options...
Doum Posted March 31, 2014 Share Posted March 31, 2014 (edited) Hey magneto, Did the hituv or hitpos attribute could be a solution ? Edited March 31, 2014 by Doum 1 Quote Link to comment Share on other sites More sharing options...
magneto Posted March 31, 2014 Author Share Posted March 31, 2014 Thanks Doum, I am not sure how to use them to trigger new emission though? I would have thought that I could set the Impulse Activation of POP Source in VEXpressions but it doesn't support them. Quote Link to comment Share on other sites More sharing options...
Doum Posted March 31, 2014 Share Posted March 31, 2014 I would like to help and give a try on my side, but I'm in a rush for the week, I have to deliver a shot and my computer is working on a sim right now taking all the power . I've this hip file, I hope it can help you. Rnd_v01.hip 2 Quote Link to comment Share on other sites More sharing options...
magneto Posted March 31, 2014 Author Share Posted March 31, 2014 Thanks alot Doum, exactly what I needed to see 1 Quote Link to comment Share on other sites More sharing options...
magneto Posted April 2, 2014 Author Share Posted April 2, 2014 Ok I finally explored Doum's file and it works great but I noticed 2 things: 1. When you spawn your particles, it seems like the new particles inherit all attributes such as life from the original particles even though you set them in the new POP Source as well. So if you set the life of the new particles to 5 and the original particle life is 100, then they also show up as 100. Is this normal? 2. I see that the new particles are spawned at the particle location of the old particles, which is fine. But how can I spawn the new particles on the surface of another SOP? So just like when you have a SOP and you use this in your POP Source, I want to be able to arbitrarily emit new particles anywhere on this other surface. I tried it for an hour but so far only got Doum-style emission working, not brand new surface emission Quote Link to comment Share on other sites More sharing options...
Doum Posted April 3, 2014 Share Posted April 3, 2014 Hey Ryan, About the particle life, there is a bug/problem, they are always adding the particle life of there parent. I've logged the bug. You can by the way by pass this by going in the pop replicate/Sopsolver/setup life(vopsop node) and plug the add directly in the bind3(life) param. There is another problem with pop replicate, inherite velocity doesn't work as expected too. When inital velocity is set to Use inherited velocity and value is different than 1 it will also change there parent velocity... Change it to add to inherited velocity to workaround the problem. Tell me if you find something else which doesn't seem to work properly. I'm not sure If I understand your second question. You want to emit from another sop when a particle touch it ? I need more infos/example. I like that kind of question to test some part of the software I've never touched yet Cheers Doum 1 Quote Link to comment Share on other sites More sharing options...
magneto Posted April 3, 2014 Author Share Posted April 3, 2014 Thanks Doum, exactly what you said I had to set life using POP Wrangle afterwards so they had shorter life. I also noticed setting Inherit Attributes to "" instead of * seem to work a little better. I assume if you inherit everything then after your particle is created, the original attributes like life, etc overwrites your own initial attributes. As for the second question, basically think of 3 objects, A, B, and C. I am emitting particles from A which collide with B, and as soon as any collision happens, I want to emit particles from C just like A, using surface emission. Does it make sense? If not, I could make a simple file for you. Quote Link to comment Share on other sites More sharing options...
Doum Posted April 3, 2014 Share Posted April 3, 2014 No that clear, that what I though and maybe I have a idea how it can be achieve. I'll keep you update with my progress. Quote Link to comment Share on other sites More sharing options...
magneto Posted April 3, 2014 Author Share Posted April 3, 2014 Thanks alot Doum, I tried using the Surface option, but then I got no emission and tried everything I could think of. I must be missing something Quote Link to comment Share on other sites More sharing options...
Doum Posted April 3, 2014 Share Posted April 3, 2014 I'm thinking about adding an attribute on the collision object and use it for emission in the POP source node. I don't think I'll have time today to play with that. 1 Quote Link to comment Share on other sites More sharing options...
magneto Posted April 3, 2014 Author Share Posted April 3, 2014 (edited) Do you mean on the collision object ( B ) or C? That gives me an idea, for using both A and C for emission and only spawning from A using an attribute but then I will have the same emission style in both objects as opposed to 2 different styles like one regular emission, the other shorter impulse emission. Edited April 3, 2014 by magneto 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.