herr.ja Posted October 20, 2019 Share Posted October 20, 2019 Hello houdini masters! I have small issue, in popnet. Im trying to create moving particles on plane, but with different "speed" U can see my intention on scheme down here. Can u guys please help me? I will be very grateful for any advices. Thank u very much!! particles_issue.hip Quote Link to comment Share on other sites More sharing options...
Drughi Posted October 20, 2019 Share Posted October 20, 2019 You can use length of P to control the speed. Something like this: v@v *= fit(length(v@P), radius_min, radius_max, max_drag, 1); 1 Quote Link to comment Share on other sites More sharing options...
herr.ja Posted October 20, 2019 Author Share Posted October 20, 2019 Hey Drughi OMG! How u guys are doing that?! works.... thank u so much!!!! But how to make it with multiple "center points". I mean more centers with slower motion of particles. I tried something in popnet/ pop vop, but unsuccesfully.... particles_issue.hip Quote Link to comment Share on other sites More sharing options...
LucaScheller Posted October 21, 2019 Share Posted October 21, 2019 (edited) Hi Michal, the LYNX_force from the LYNX VFX Toolset can also do this, but more user friendly/interactively with customizable falloffs, see this video for more info. You can grab it for free here: https://github.com/LucaScheller/VFX-LYNX Cheers, Luca Edited October 21, 2019 by LucaScheller Quote Link to comment Share on other sites More sharing options...
jamesr Posted October 21, 2019 Share Posted October 21, 2019 On 10/20/2019 at 2:26 PM, pan.mentolka said: Hey Drughi OMG! How u guys are doing that?! works.... thank u so much!!!! But how to make it with multiple "center points". I mean more centers with slower motion of particles. I tried something in popnet/ pop vop, but unsuccesfully.... particles_issue.hip Hi, your issue is in the pop drag node. You have "@falloff" in the activation slider, which is deactivating the whole node, because that expression isn't valid for that parameter. Think of activation as like a "global" parameter for the node. It can't be changed per particle, it's either on or off. Instead, you should leave Activation to 1 and use "VEXpressions" to multiply the drag (airresist) by your custom attribute. Also, you have "0.798" as the point number for your distance lookup in the VOP where you set the f@falloff attribute. You should be careful that it is set to the correct point number. Nodes changed are in red. particles_issue_jamesr.hip Quote Link to comment Share on other sites More sharing options...
herr.ja Posted October 23, 2019 Author Share Posted October 23, 2019 On 22. 10. 2019 at 12:02 AM, jamesr said: Hi, your issue is in the pop drag node. You have "@falloff" in the activation slider, which is deactivating the whole node, because that expression isn't valid for that parameter. Think of activation as like a "global" parameter for the node. It can't be changed per particle, it's either on or off. Instead, you should leave Activation to 1 and use "VEXpressions" to multiply the drag (airresist) by your custom attribute. Also, you have "0.798" as the point number for your distance lookup in the VOP where you set the f@falloff attribute. You should be careful that it is set to the correct point number. Nodes changed are in red. particles_issue_jamesr.hip Thank u so much James, now it works! I added more "falloffs" and it works perfectly!!! Can I ask U one more time? I have problem to put particles just inside of the object (i mean not sliding on the surface, but flowing just inside of the geometry). I tried poplimit node, but this works just like BoundingBox, and I need to defined it by my specific geometry... maybe u can help me fix this too... And Thank u again for your previous explanation and help. cheers pop_inside_issue.hip Quote Link to comment Share on other sites More sharing options...
jamesr Posted October 25, 2019 Share Posted October 25, 2019 Sure. In your note you say Quote I need to let flow particles just inside the testing geo. But keep them all inside, by bouncing from the surface. "by bouncing from the surface" you mean act like a normal collider, just inside right? Like have the particles bounce around the inside? That's how I read it. Added/changed nodes are in gold. pop_inside_issue_jamesr.hip Quote Link to comment Share on other sites More sharing options...
herr.ja Posted November 25, 2019 Author Share Posted November 25, 2019 On 25. 10. 2019 at 7:04 PM, jamesr said: Sure. In your note you say "by bouncing from the surface" you mean act like a normal collider, just inside right? Like have the particles bounce around the inside? That's how I read it. Added/changed nodes are in gold. pop_inside_issue_jamesr.hip Hey James! Sorry for my very late reply. I was quite bussy for long time. I fixed this problem by myself but it was done by very hard and crazy kind of way... I like your approach... thank u very much for your help!!!!! Quote Link to comment Share on other sites More sharing options...
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