Hi Im new at houdini and i'm amazed by the endless posibilities Im trying to animate noise texture inside vopsop i've created inside geometry (that i've converted to particles) to update the viscosity settings for the particles over time, but when im trying to animate im getting this messege: “cannot have channels which depend on time”. How can i set the particles viscosity parameter animated OVER time ? Thanks very much !
to Animate VOP nodes , you should first promote this parameter then animate it in outside of the VOP network ! Just press MMB on the your specify parameter , then choose “Promote Parameter” , This parameter should be add to VOP SOP parameters in the Geometry network.
I've trye'd it allready.. but the fluid solver ignores the changes over time and refferes only to the first frame state.. should it work ? and i've done something wrong somewhere ? Thanks
So if you wanna change viscosity attribute over time with some VOP node such as Noise , you should do it in the SOP Solver in the AutoDopNetwork, Not in the Geometry network ! Just connect SOP Solver node to last input of the Flip Solver and add your VOP SOP node inside of the SOP Solver :wink:
First thanks very much you'r very kind..! second: is there's any way to map the noise to the particles first state (frame 01) ? because now the noise texture is floating.. Thanks
very important note is you should chenge Input Type option for flipfluidobject1 to Particle Field , Because in the other option , UV attribute doesn't import to the Dynamic network , Also you should add Fluid Source to the MODEL too. check edited project :wink:
b.t.w. can you address me to some good tutorial on how can I cache the fluid particles to disk (fetch?) with particular reference to the file size optimization, and how to keep only channels that I want to export? (And of course how to import them later
I think the best way is using "Rop Output Driver SOP" for writing particles to bgeo files and read them with File SOP. Also you can use Attribute SOP node to delete unwanted attributes before writing them. But check these Topics for learning another methods such as Explicit Cache , ROP Output driver DOP :
For the noise, you can also use a rest position before sending it to dops. Then you can use rest instead of P for your noise lookup.
Side note: You can do cool stuff using rest positions and fluids: http://fx-td.com/?p=329 [fx-td.com] Getting the noise to move with the fluid but then fade between two rest positions to help remove the smearing you'd get otherwise.
Solitude For the noise, you can also use a rest position before sending it to dops. Then you can use rest instead of P for your noise lookup.
Side note: You can do cool stuff using rest positions and fluids: http://fx-td.com/?p=329 [fx-td.com] Getting the noise to move with the fluid but then fade between two rest positions to help remove the smearing you'd get otherwise.
Yes , I forgot rest position , I think this is so better than my method , specially thanks :wink:
Uv's are good too depending on the situation and what you want stuck to the particles. The cool thing about rest is that you can always put the points back to rest, project the uvs how you want and then copy the uvs back onto the animated points.
Thanks guys..! But I don't know where exactly to place the rest position, if I'm using “surface” or “particles” for the flip input.. (does it matter for it?) Thanks again!
Thanks! Is there any way to do rest position for particles with “surface sop” input inside the “flipfluidobject” instead of “particle field” input ? Thanks!
What do you mean? The uvs will stick to the the particles the same way rest would as long as the uvs are projected on the rest state. You can put the particles back to rest, project uvs, and then attribcopy the uv over very easily. Unless you mean something else…? I could modify my rest field setup to convert it uvs instead if you needed.
