bunker

you can use the fit function for that: float drag = fit(@P.y,0,10,0,0.1); // zero drag at y=0, drag or 0.1 at y=10 v@vel *= 1-drag; if you want to clamp the velocity it's a bit different: float maxspeed = fit(@P.y,0,10,100,1); v@vel = normalize(v@vel)* min(length(v@vel),maxspeed);

also have a look at upresing your sim, you don't always have to sim everything super hires to get good details there are a few threads about that, for example:

yes, go for a good Wacom, takes 2-3 weeks to get used to it but after you won't go back, and it's much faster than a mouse for everything (and silent) Sitting badly is also a source of wrist pain, try a standing desk.

try the "centroid" expression instead: centroid("../mynode",D_X),centroid("../mynode",D_Y),centroid("../mynode",D_Z)

yes, that seems a bit like doing some of the FLIP solver - could be a cool science project if you have the time Things have a changed a bit in 9 years, computers are much fasterand have a lot more RAM too... just curious, what are you trying to do?

dual rest won't give you sliding artifacts but would might get some pulsing effect when blending between rest and rest2. I really depends on the speed of your smoke/pyro sim. Using particle is a cool idea but sampling them properly not easy. How do you sample rest/normal attributes when a lot of particles overlap, and what areas with very few particles?

you probably need to combine gradient and dual rest.

you need the upres density, heat, and temperature and the lowres vel from frame 71. the upres vel is re-created on every frame using the lowres vel. I included 2 examples on how to set the initial heat field with sopSolver and wrangle. set_heat.hipnc

old thread but I thought I'd add this: you just need to zero out all the fields inside the collision - with a volumewrangle: // sample collision (input 0 in the collision field in SOPs) float c = volumesample(0,0,@P); if(c<0)f@density=0;

you would have to set your sim startframe to 71, and copy all the fields from frame 71 as your initial frame. The smoke object has an initial data tab where you can set density/temperature/fuel/velocity, you'll need to add heat also. you can use a sopsolver or a volumeWrangle for example.

normalize them and multiply them by your magnitude. eg: v@v = normalize(v@v)*chf("magnitude");

to visualize the pressure field go to smokeobject/smokeconfigureobject/pressure_data and plug a scalarfieldvisualization DOP or you can create your own field with a gasmatchfield, copy the data and use the same scalarfieldvisualization

you probably want this which should be default IMO: You can save it as default in >Edit->Preferences->3D Viewports.

by COPs I think you mean CHOPs You should have a look at the ripple solver before going full FLIP, it's much faster for what you need.

yes, that works great.