anupamd Posted August 1, 2011 Share Posted August 1, 2011 (edited) Just curious if there is a way to control simulation attributes per point? For example, if I have a fluid flowing over a surface, and want the friction coefficient of the surface to vary across the surface using a noise pattern..so that the fluid breaks up in an organic way as it flows down. (this would be a nice way to get good detail without using complex collisions) Perhaps another way to do it is to vary the separation scale per fluid particle, to get a sort of per-particle viscosity. Or.. perhaps if all we are doing is modifying the divergence field, some way to modify the existing divergence field to get the desired result? Either way, these are great ideas however I do not see a way to get at the data and manipulate it. I dont see this data existing as a scalar/vector field anywhere. Any help would be great thanks! - Anupam Edited August 1, 2011 by anupamd Quote Link to comment Share on other sites More sharing options...
lukeiamyourfather Posted August 1, 2011 Share Posted August 1, 2011 I realize you are asking these questions about Houdini but RealFlow does all of those things out of the box without modifications to the solvers. I've found the SPH and FLIP tools in Houdini to be good for small/quick effects but for larger or more complex fluid simulations RealFlow is much more intuitive, featured and faster. Especially when Houdini is calculating SDF for animated objects with many substeps, the performance is so bad it becomes pretty much unusable. Creating non-Newtonian fluids in Houdini could be pretty ugly as I don't think the solvers have that already integrated. I don't have the knowledge to suggest how to do it in Houdini but I'll be watching as I'm curious as well. Good luck with the shot. Quote Link to comment Share on other sites More sharing options...
anupamd Posted August 2, 2011 Author Share Posted August 2, 2011 well the sim Im doing is fairly simple and it can be low res (the low rez fluids will be driving some other effects, the the fluids themselves wont be visible). I just figure with all that houdini can do, there has got to be a way to get a little more deeper control. Any fluids expers out there.. Bunker, PClaes? =) ps: I dont think I can avoid not using realflow for much longer though, so I'm going to start messing with it. The RF to houdini dop is pretty solid from what I hear and imports just about every attibute. Quote Link to comment Share on other sites More sharing options...
Stalkerx777 Posted August 2, 2011 Share Posted August 2, 2011 Just curious if there is a way to control simulation attributes per point? For example, if I have a fluid flowing over a surface, and want the friction coefficient of the surface to vary across the surface using a noise pattern.. Hi.It can be done very easily in houdini. Here is an example. I paint friction with a paint SOP here, but you can do whatever you want to set "friction" attribute. You can use texture,vops or any procedural approach.Same with most of the other attributes(mass,bounce,velocity,stiffness...etc.) Good Luck. paint_friction.hip Quote Link to comment Share on other sites More sharing options...
lukeiamyourfather Posted August 2, 2011 Share Posted August 2, 2011 Hi.It can be done very easily in houdini. Here is an example. I paint friction with a paint SOP here, but you can do whatever you want to set "friction" attribute. You can use texture,vops or any procedural approach.Same with most of the other attributes(mass,bounce,velocity,stiffness...etc.) Good Luck. paint_friction.hip That's a great example for the object attributes. I wasn't aware they could be passed in an attribute like that. Any thoughts on non-Newtonian fluids in Houdini? Quote Link to comment Share on other sites More sharing options...
bunker Posted August 3, 2011 Share Posted August 3, 2011 (edited) @lukeiamyourfather have a look at this thread : I hope you get some discount on your next Realflow license That's a great example for the object attributes. I wasn't aware they could be passed in an attribute like that. Any thoughts on non-Newtonian fluids in Houdini? Edited August 3, 2011 by bunker Quote Link to comment Share on other sites More sharing options...
anupamd Posted August 3, 2011 Author Share Posted August 3, 2011 AS usual, someone posts a hip file that totally opens new doors for me. Love love love this forum. Thanks! Im digging further into this right now, i'll post some tests if I produce anything interesting. @lukeiamyourfather have a look at this thread : I hope you get some discount on your next Realflow license Quote Link to comment Share on other sites More sharing options...
lukeiamyourfather Posted August 12, 2011 Share Posted August 12, 2011 @lukeiamyourfather have a look at this thread : I hope you get some discount on your next Realflow license I don't see anything in that thread about non-Newtonian fluids. Looks like a discussion about high viscosity fluids to me which are not the same thing. Is there a specific post I missed? I assume you're being sarcastic about the RealFlow discount in which case the snide remark was unnecessary and unprofessional. What's wrong with choosing the right tool for the job? Go browse the RealFlow forum, where appropriate I recommend Houdini and other tools (if I think they are the right tool for the job). Quote Link to comment Share on other sites More sharing options...
syntheticperson Posted May 1, 2018 Share Posted May 1, 2018 Has anyone been able to get friction attribute to work with the bullet solver? It works with the RBD mode in the rigidbodysolver node. However, if I switch it to Bullet, the blocks slide, ignoring the painted friction attribute. paint_friction_BulletNotWork.hipnc 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.