woodenduck Posted January 11, 2013 Share Posted January 11, 2013 Hi guys, I'm trying to create areas of varying friction on a fluid collision object, but I'm not having much luck. I've created an attribute (stickscale) on the surface and and painted in where I want the fluid to flow fast and slow. But this isn't being picked up in Dops. On flipsolver/ volume motion/ collisions/ stick on collision, I can see it's looking for stickscale attribute, do I need to explicitly state somewhere that I want to use the value coming in from Sops? I also tried collisionvelscale, but to no avail. Any thoughts or tips would be very welcome, Thanks, WD Quote Link to comment Share on other sites More sharing options...
ryew Posted January 11, 2013 Share Posted January 11, 2013 Can you post an example scene of your settings to check? Quote Link to comment Share on other sites More sharing options...
bloomendale Posted January 11, 2013 Share Posted January 11, 2013 (edited) If you're talking about gas field VOP "stick_on_collision" inside flip solver then it just don't know that you have some points with "stickscale" attrib on them. It's more like Volume VOP and works with volumes. I think you could bring in points as pointcloud and find nearest for every pos and sample attrib. But it would be very slow. Instead you can create volume out of this points to represent "stickscale" attrib and bound it to parameter in the the gas field VOP "stick_on_collision". I'm not familiar with flip solver so there is may be shorter ways (already built-in). But this is how "Viscosity/Density/Divergence by Attribute" setting works edit: Attached very rough sample scene. Again. flip solver may have some built-in features for that. I just don't know) 3ak_flip_stickscale_from_geometry.hipnc Edited January 12, 2013 by bloomendale Quote Link to comment Share on other sites More sharing options...
sadhu Posted January 12, 2013 Share Posted January 12, 2013 How about adding friction attrib on collision object? paint_friction_for_flip_fluid.hipnc 2 Quote Link to comment Share on other sites More sharing options...
bloomendale Posted January 12, 2013 Share Posted January 12, 2013 How about adding friction attrib on collision object? So there IS built-in way) But i must say it's kinda slower (maybe cause stickscale attrib kills the velocity and friction kills the acceleration and is overall more complex?) and i can't force liquid to just stop and stick to collision object, even increasing friction to 500k. Quote Link to comment Share on other sites More sharing options...
sadhu Posted January 13, 2013 Share Posted January 13, 2013 (edited) maybe cause stickscale attrib kills the velocity and friction kills the acceleration and is overall more complex? Can someone tell me how does friction work? Help (physical params dop) says it governs how much the tangential velocity is affected by collisions and resting contacts. I didn't see any setup(or did I miss it ?) which uses friction to affect vel or accel. Is it a hidden process? Does it act as a simple multiplier on vel or accel to reduce their values? Edited January 13, 2013 by sadhu Quote Link to comment Share on other sites More sharing options...
woodenduck Posted January 14, 2013 Author Share Posted January 14, 2013 Thanks guys! Bllomendale, this is very effective if a touch convoluted, but certainly faster. Sadhu, very simple, I was painting the wrong attribute! Quote Link to comment Share on other sites More sharing options...
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