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Showing results for tags 'density'.
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Hello everyone, I'm working on a very specific earth/ground blast. Inorder to keep the max control I decided to create pre sim wich would be used as a source for the main simulation later. Or I'm going to build it in directly and blend it with a pyro solver over time. Anyways, the goal of my setup is to create blast trails wich have an outward momentum. But having a vel field wich pushes density outward causes mushroom with a pyro solver because of the nature of divergence correction. A custom solution should help me out but I'm stuck cause the vel field is not expending but keeps clipping to the density source region. Even vel is advecting vel. There is already a post which seem to had a simular issue but it didn't work for me. advecting velocity by itself. Any ideas? vel_clipping_issue.hip
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Hi guys, I have two RBD objects, floating on FLIP-fluid. I set the Density (mass) to 400 (lower than the fluid mass). When two objects are of the same amount of mass, they have to react in the same way, right? I mean in this case, they have to stay on the surface. The problem is the bigger object stays on the surface, but the smaller one sinks into the fluid: - How can I fix it? - How can I set the density(mass) in the SOP level (as an RBD source)? Thanks for helping. Floating RBDs.hip
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Hey folks, proud to present LYNX Tools, a collection of production proven open source tools to accelerate your workflows! All mentioned tools are free to download via the links below and are licensed with a full HoudiniFX license. All Houdini Assets have complete Houdini native documentation available. Repository: https://github.com/LucaScheller/VFX-LYNX Lastest stable release: https://github.com/LucaScheller/VFX-LYNX/releases Please give them a test drive, so we can improve them further Roadmap | https://github.com/LucaScheller/VFX-LYNX/projects/1 So far there are three tools: LYNX_force_general | Tweak your sims with this all purpose & intuitive force field. Built to mimic force fields in other DCC applications, but with support for more features and a natural Houdini user experience. https://www.lucascheller.de/vfx/2019/03/24/vfx-lynx-houdini-force-general-asset/ LYNX_fabric | Create fabric/weave patterns with ease. Perfect for creating that holiday sweater you never wanted. https://www.lucascheller.de/vfx/2019/03/16/vfx-lynx-houdini-fabric-asset/ LYNX_velocity | Get control of your velocities via an intuitive UI or groom them for absolute fine tuned control. https://www.lucascheller.de/vfx/2018/11/01/vfx-lynx-houdini-velocity-asset/ More info on my website, including full release logs: https://www.lucascheller.de/blog/ Houdini User Group Munich Presentation: https://vimeo.com/334887452
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Hello guys, As you know, the default attribute value of "Density" in Flip-Fluid is 1000. Now, in a simulation with two amounts of "Densities" (e.g 1000 and 100), what is the best way to speed up the rising speed of low-density fluid particles? I want to force them to reach the fluid surface as fast as possible (maybe something like the buoyancy parameter, in the pyro solver). Thanks for helping.
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Hi all, I generated a mesh, which I converted in volume, then used a box with vdb combine to limit my volume to that box. Problem is near the bounds, the density is fading away. Is there a way to avoid this and keep true density? Thank you, mrblimack
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Im working on a pyro simulation using axiom solver. I have an animated tiger in scene, I then use MOP_Spread to animate the @mops_falloff from head to tail, then I multiply @mops_falloff with @density to have the density source animated. As you can see the density is smoothly transform from 0 to 1, but when I run the simulation with sub step by 2, there's some point the density spawn even though the density source has not yet reach to the point. Is there anyway to fix this matter? Thks in advance. pyro spread.hip 03_Anim_Xich_Ho_intro.fbx density_source.mp4 axiom_solver_problem.mp4
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Hey Everyone! I'm doing an RBD sim of multiple objects colliding. I am merging them and plugging then into the rbdbulletsolver. Does anyone know how I can modify the weight/density of one of the objects so it reacts differently to the other objects? Thanks so much!!
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Hello, I am trying to work with OpenCL but as soon I enable them on few nodes, like the gas disturb, gas turbulence, it stops working. I just get a mushroom smoke effect. Does openCL not work on these fields? I have attached some screenshots. The first image is without OpenCL, the second one is with smoke disturb disabled and the third image is with openCL enabled on Smoke disturb.
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Hi everyone, did a pyro sim along with a collision object. When I up the density from 1 to 4 in the pyro shader, the voxels are getting visible (attached an image to the post showing the issue). Is there any way to prevent that or soften the voxels on the outside in a post process or something? Cheers, Christian
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Would it be possible to have a sphere primitive or any geometry affect the density of a volume (fade density from 0 to 1) based on distance between the geometry's pivot (or all points) and the volume?
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Hello,I have 2 questions about the hair:1. When I paint the density attribute the hair guides are reacting based on the vertices, i.e. when I hit only a vertex guides disappear (or appear). It means that with low polygon count I can't avoid stepped guides boundary. But with more subdivisions it is practically impossible to work due to long cooktime after each brush stroke… How can I deal with the guides between the vertices without increasing subdivision? Attachment below describes it.2. To delete hair guides (for example, for hairline or beardline on the head) I use Length Adjust shelf tool with Target Length value of 0.001 (complete 0 is impossible), but this still leaves hairs roots as dots when rendered. Is there a cleaner way to delete the hair neatly along the boundary?
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Hello! So I have been Having lots of problems to setup the pyro sim on a large scale. Somehow I cant manage to understand the propper settings. I would love a result similar to this: The size of the my sim is 1:10th of the real size because as I make the sim bigger the problems also get bigger. I guess it has something to do with the source density and the smoke object Take a look on how awful it looks down below (I am quite new to this soft) I am leaving the whole proyect full of notes so you have an easy time helping me Thanks a lot and I am looking forward to learning. cya NaveVolando.rar
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Hi everybody, I am new to houdini and i am already scared. I know how to emit pyro from colors by using ramp than a delete node with a $CR < 0.1/.5/.8. on my emitter it work but i want to control the "density" of the emission based on the gray level of my ramp/paint node. Meaning white zone = 100% emission dark zone = 0% thanks you
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Hello I am trying to mix/combine the density and colour of two different VDBs into one VDB in Houdini (image 1, file attached). For the most part, this is working as desired but there are two main issues: 1. Pink fuzzy edges around the blue VDB - How do I get nice clean edges where the blue VDB smoothly fades out to transparent? (image 2) 2. Blue VDB does not go all the way to the border of the pink VDB - How do I make sure both VDBs finish on the same outside border? (image 3) I have tried adjusting the voxel size, changing the set up of the VDBs (ie. the exterior/interior band voxels, fill interior) but I can't seem to get it working the way I want. Can anyone please help me? I have only been learning Houdini for just over a month so example files would be helpful. Thank you! Mix VDBs.hip
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Hey, total noon here Just started learning houdini recently. Made a candle flame and adjusted it like I wanted it. When I am converting it to VDBs I can't get the density right and thus it looks wrong or is invisible in maya. The file is attached, any help is appreciated CandleJet.hip
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Hey guys, I'm making a smoke a sim of a person blowing out smoke (vape smoke) and when the smoke starts to dissipate and get's close to fully disappearing the resize fluid dynamic container just shrinks and clips that area entirely. Looks very jarring and obvious fake. I don't know why this is happening. It still happens when I increase my substeps to 3 so I don't think that's the issue. When it's at substeps 1 - the clipping still occurs but more smoothly (if that matters). I've attached my scene file and a flipbook of the crime. I'd really appreciate any help with this! Smoke_03_ForReddit.hip Pyro Clipping_For Reddit 2.mp4 -
Hey, So i im having this small issue where I think the fuel? is showing in the render and it is ruining my pyro sim to look like a clean flame. I have density turned off, so there is no smoke and temp and heat are the only attributes being used in the material node. I'm assuming fuel is the source of the issue and it is being rendered through heat. Any ideas on how I can remove that small cloudy emission on top of the flame (in the picture below), in the video you can see it in the middle of the flame, you can see it on the 2nd and 3rd one but it doesn't seem to appear on the the black body one (1st one) It seems to only happen when I use the ramp to colour the flame
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I'm trying to recreate an ultracentrifuge that seperates high density particles from low density particles. My current setup is two fluids with separate densities being emitted side by side to fill the container. Then once the container is fully filled I start up the "centrifuge", a pop axis force to spin everything at high speeds. The problem is it just acts as a blender and not a separator. I have a little divergence to pump up the fluid in the beginning but then it's removed. The densities are about 400 kg/m3 apart. I've tested fast and slower with different drags and settings but still just blends. Anyone else try something like this? Maybe I'm missing something important (more than likely, ha). Thanks! Update: kind of working now adding some mass, drag, and applying the rotation only to the low density particles. Faking it till it makes it I guess.
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Hey guys! I'm working on a project using fluid to simulate a drop (something like oil drop) falling and colliding with an object. The thing is that the client ask me if I can separate the drop when colliding with the object in another smaller drop and I don't know how can achieve that, I'm looking for something like have different density in the same fluid object or select some particles inside that can be affected for another force but the fluid is fluid, not particles so I'm lost in that! BTW this is the sim (the second part is the fluid). Cheers! gota v1.mov
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Hi!! I have subdivided the primitives of an icosaedron. What I want is for each primitive, to select a random number of subdivisions (the small black triangles) , extrude them and control their density with an attribute. How can I do that?? POPULATION -HAPPINESS.hipnc
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Hey guys! Trying to figure out the whole custom vectorfield aspect of the pyro solver, but running into some issues.. I created a new vectorfield (Cd) under the smoke object, importing a Cd vectorfield that i want to use in a source volume node (replaced velocity with Cd to Cd as another forum post on here suggested). Then I added a gas advect field microsolver to the advection input of the pyro solver. With the multi checked on the visualization and Cd in for diffuse, I can see that the vectorfield is properly being sourced, but it doesnt advect by the velocity field for some reason, it just sits there. The gasadvectfield node should move the Cd by Vel right? I've found some good forum posts about this here, but for the life of me can't replicate the effect. Any suggestions / advice? Thanks! Cd_advect_v01.hiplc
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Hi, I want to render a custom pass for clouds in mantra. The reference jpg shows a custom pass from Maya (density / ambient) and the alpha for the same clouds. In Maya a gradient ramp was used on the incandescence channel. Basically where the clouds are denser should be black and the opposite, for lower density I should have white. Can I replicate that with mantra? I'm using the sky rig tool so everything is calculated at render time. Thank you!
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Vex volume procedural density doesn't scale
alican posted a topic in Lighting & Rendering + Solaris!
I am doing pcopen in cvex to to render points as volume but for some reason I am not able to scale the density as much as I want. It looks like it is clamping the density values and doesn't allow me to go higher. When I use smaller IFD bounds this problem fixes itself but also it cuts my overall object. Also vex volume procedural doesn't seem to work with new mat context. Thanks for the solutions, Alican -
Hi Guys, I need some expert advice and insights on this project I'm working on. I'm doing some RnD first before moving to bigger scale so I can provide you guys with the HIP file. The objects however (barrels and table pieces) I cannot share with you. But maybe there's something in the dop nodes or solvers that you can spot right away. I'm working on a flood scene where there's a lot of debris and rubble that needs to be transported by the water. Please have a look at the video. The barrels seems to acquire a spin which at one point is out of control! I can imagine this could be the rotational stiffness... but the exploding (and stuck) piece of table is still a mystery at the moment. As you can see I'm also having trouble controlling the buoyancy of the objects in the fluid. Right now I use the density to try and float pieces but it's not entirely working the way I want it. To sum it up: - The wooden planks need to float - barrels need less spin and need to be embedded more in the fluid. - the tables obviously need to stop launching like superman . any advice or tips are greatly appreciated . High-RBD_count-in-fluid-006.hip
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I've been getting back into FLIP, and trying to replicate this test done in Naiad a while ago: https://vimeo.com/25020677 Using some POP nodes, I know I'm getting attributes changed on the points properly, but I can't figure out why the solver isn't pulling the higher density particles down under the lower density ones. I even played with @mass, hoping that'd do it, but it doesn't. The POP nodes are affecting the points just fine; when I crank up viscosity/velocity/color, those are set properly. The red points should be rising up, and the teal/blue ones should be sinking since they're heavier: Does anyone have some insight(s) as to why the density isn't making points rise/fall? Thanks! dense_flip_separation.hipnc
