Sophie

Hey, when I load your file it doesn't seem to be working properly. However, in your switch node, you're using @class%2==0. As far as I know you can't use attributes in a switch like that. Try getting the attribute like this: prim("../foreach_begin2", 0, "class", 0) % 2 https://www.sidefx.com/docs/houdini/expressions/prim.html Hope it works!

I'm not sure if you need the length for anything else, but if you want to match the bounds of something else, maybe you can just use a matchsize node I've attached a very simple example of this match_size.hip

Here is the file! River_flowrate_v2.hiplc

Yes, I have indeed constructed my river based on a curve that I gave a width attribute. I will have a look into this derivative! Sounds like it could be just what I need I will also still upload my hip file later, since I can't get to it right now. Thanks!

Do you mean you want to set the width of the geometry that you have of the line, over the length of that whole line? Because then you can create a width attribute for just that line that is controlled by a ramp.

Hi there, For a school project I am working on a river. I am getting very nice results with the standard flowmap tools already, but I wanted to change some things. First of all, I wanted the river to flow quicker where it is narrow, because velocity = flowrate/area. This does work. Note that to make this work, I went into the flowmap to color node and got rid of the normalize, because I want values over 1 for the speed. Then I also wanted the water to flow quicker, so I thought I'll just take v.y and multiply it with 9.81. This seems to work at first hand, but then at the top of the slopes of my river, the water seems to flow in the opposite direction (back up). I am not entirely sure why this happens. When I set the gravity to a lower value, like 3, this doesn't really happen yet (or at least not visible). Can anyone explain to me why this is happening? Also, is there a better way of achieving this result, rather than just not normalizing any of the vectors?

Wow, looks pretty complicated! Tried to recreate it, but as soon as I start playing the sim in the dopnet, it keeps loading forever until it freezes. Must've done something wrong! Curious, will this work with larger scale simulations too (or in other words, is there a reason you made it quite small)? [EDIT] I made the smoke object way too big... It is working now, but as soon as it collides with the top of the container, all the smoke disappears. I haven't found out yet why that happens. Only thing I've found is I don't seem to have a dead attribute. It seems to just be there in your file from the pop source onwards, but for me that is the only one I don't have Any suggestions? Is this my problem or is it probably something else?

Hi there, I am learning about smoke in houdini and I am desperately trying to achieve an effect like this By this I mean a fast paced smoke puff that spreads out wide, like almost in a V shape. However, no matter what I do, my smoke always ends up looking very straigt. I can achieve the fast paced but then it looks even more straight I think. I tried making it faster by chaning the time scale, giving it a high buoyancy lift, using my normals as a velocity volume (in source volume node) and setting the scale of it to very high, setting the temperature scale to a higher values, etc. All these individual things work for the speed, but I keep ending up with quite a straight line, or something that isn't making sense at all. I tried adding turbulance, but this also doesn't help me to achieve that "v shape". I hope someone can explain to me what is going wrong, because I am totally lost.

Could anyone tell me what rop node this is? Do you need like a plugin for redshift? Haven't used it before and would love to try!

Okay, thanks! Yeah I thought it was mostly in my riverbed, because if I tried with more "simplified examples, it still decreases, but it looks better. For now I was surfacing another result that I had last weekend, so at least I have something that looks decent, because I also still want to look into white water :/... I will definitely keep trying with the fluid from object though! I'll try maybe rotating my river bed indeed, or making an obstacle that is not visible in the render (or both).

I added a file that I sent to someone else earlier today, of how my setup was this afternoon. This is the V8 file. The other one, is how they adviced me to try it with both a flip from object and a separate emitter at the top. Ii haven't reached any nice results yet. They also said to try and add more trees at the bottom, so the fluid can't escape as quick. Or otherwise just a box that blocks of part of the end, so it can't flow out as quick as well. Rapids_BigV8.hipnc Rapids_BigV9.hipnc

Thanks again for the video, will definitely watch it! About the leaking: I made the fluid container a bit bigger at the bottom and turned of the geometry to see if the particles falls through the ground, but that doesn't happen. I noticed the particle count is decreasing. I am not entirely sure what you mean when you say keep the particle count constant in the emitter. Do you mean when using this flip from object? And do you mean the boundary layer then? Because I tried that as well, but that didn't really look nice and the teacher said I shouldn't need it. For the color... I cached the fluid in my scene, opened it with another scene, load the file and give it a color with a ramp from attribute. Then I have the values 0 0 0.9 for the first point in the ramp 0 0.9 0.9 for the second point in the ramp and 1 1 1 for the last one. I did this to try and get the blue gradient that you get with looking within the dopnet, but that didn't turn out too well. Anyway thanks again for the video! Gonna see if this will help me

Thanks for the video's! Now that you mention it, I have seen them before but I didn't remember. I tried using the flip from object, but for some reason I lose all the volume. I tried decreasing the particle radius scale and change the particle separation. My teacher said I shouldn't have to use the boundary layer. I checked my collision too, and it looks like that is working. Any ideas why this is happening?

I did run it a few hundred frames before and then gave it an initial state and let it run again, but it didn't do a lot. I have to admit my particle separation was a bit bigger there. I attached the file now as well, thanks ProjectBlockC.hipnc

Hi, I am working on a flip simulation of a rapid for a school project. I noticed my water only builds up a super thin layer of particles, so it doesn't really fill up the river bed. I tried making the particle separation different in the emitter and the dop network, but that didn't work. Someone also said increase the emission rate. To do that, I tried to increase the scale source volume, but that also doesn't do anything... Any ideas?