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Found 15 results

  1. Hey, i am fairly new to houdini and especially to redshift. I have a setup with particles and want some particles to be emitted by a specific distance. I use the particle color as base color and want my attribute to drive the emission strength. If i use mantra everything works fine. Couldnt find any solution. Cheers and thanks, dom
  2. Hello, I am curious if it is possible to illuminate a volume with the light emitted from the emissive channel of a redshift material. I can't seem to find anything regarding "volume contribution" within the materials and there doesn't seem to be much documentation on the subject. For example, embers emitted from a flame should illuminate the rising smoke. Thanks! ian
  3. Hello! First time posting. I'm new to Houdini, this is my first project that I decided to do. But I'm a fairly seasoned C4D 3D generalist so I know what I want to do in Houdini, I just don't know how to go about it. I'm in Houdini 17.5. Here is the problem. I have stumbled around in Houdini and made a Viscous Flip Fluid Sim. I made a Sphere an emitter, and emitted my fluid pouring onto a .OBJ mesh that I imported in. I've cached the particle FLIP Particle simin the DOP network, the Particle Fluid Compressed Cached, and Particle Fluid Surface Cached. Now here is my problem. I exported my meshed sim as an alembic from a ROP_Alembic node. Imported into C4D. And then I realized I have a UV problem. This is a Redshift texture and shading pass that I did with my sequence. At the time I forgot to plug in the velocity data tags from the Alembic sequence into the Redshift motion vector blur, so if it looks weird, that is why. Crystal_Goo_Test.mov My texture smudges are on the mesh, but they stay static while the mesh animates. It looks just like the textures from this cartoon it doesn't move with it. So after a bit of digging I realize I don't even have UV's. Because Flip Fluids don't come with UV's, and if I never defined any UV's then how could they just magically appear? lol. So I tried researching how to generate them, and how to export them with the alembic. But for my specific situation I couldn't find anything that was up to date and worked. OR I am too much of a noob to implement what I saw in forum posts. The stuff I saw was for Houdini version 13, 14.5 and 16. I'm on 17.5. Here is a screen shot of how I tried to generate UV's and export them, again I never re-cached my sim yet. I just tried to put uv's on my existing set up. Below is my emitter. And there are no UV's on this sphere primitive, nor anywhere before the output. I took a shot in the dark and tried to see if I could generate them after all my caches (because it took 3 days to cache the fluid surface mesh). So I honestly have no idea where to generate these uv's, how to do it correctly, and how to get them passed onto the fluid mesh for alembic export and texturing in C4D Redshift. I'm including my .hip file with my cache's disconnected. They are over 200 GB's all together so it's too big to include here. Lower the substeps in the Flip Solver or lessen the Fluid Mesher to make it play back faster. I used high settings for my final export (also I tried my best to optimize, but again I'm a noob with Houdini and have probably done things incorrectly in my set up). Crystal_Viscous_Sim.zip The FLIP DOP cache might still need to be disconnected. This is the final step of my personal project. I've done all this on my own but I'm super stuck on this UV generation and export. And once I can export this fluid mesh an an alembic sequence for C4D Redshift I will be set to render. Thank you in advance for any feedback and/or answers. Please write out instructions very clearly for me to replicate if you don't want to provide pictures/ screenshots or .hip files. Again what I'm trying to do is generate UV's for my Fluid Surface, and have then be able to be exported via an Alembic sequence for texturing and rendering in Redshift.
  4. Hi, I want to emit fire from a geo and use a texture mapped on that geo to control the fire emission. I know there is a way to scatter particles on a geo and then use a texture mapped on that geo to control those particles scale and then use them to emit fuel, but I would like to know if there is a way to directly use a texture on a geo emitting fire to control the fuel amount so when there is a gradient in the texture, the fire really fade correctly instead of just being emited by smaller particles in the grey areas... also I don't like the idea to have to use a really dense mesh to have enough rez for the texture to show in the scattered particles when there are finer details in the texture (or maybe Houdini is so powerful that it doesn't bother to do this...) In the doc about the "attribute from map" node, we can read this: http://www.sidefx.com/docs/houdini/nodes/sop/attribfrommap.html You can use this node to create density, fuel, and temperature data to drive a fluid simulation. Using the Fluid Source operator, this data can become a set of volumes to be used as a source for a fluid simulation. So by "fuel data" do they mean scattered particles as emiter? Or is there a way to use that node to directly control the fuel by a texture? tanks in advance for any hint folks!
  5. Hello, I am doing a big ocean simulation where a wave is hitting a object. And there I want to create whitewater(spray) splash. But I don't want to create foam and particles to spread in the whole tank instead of that I want the particles to spread in a particular defined area, So that simulation can run fast otherwise it is taking lot of time. Is there any way to do that?
  6. Hello fellow scientists,I am currently working on a shot where I want to render out an indoor-explosion over about 50 frames. Now since I can't get my mantra render-times below 20 minutes (in FHD) I had hoped to render the volume in redshift more quickly because I have had good experiences with rendering just density in RS.The problem comes up as soon as I start to use emission with redshift. I start to get very weird boxes of emission around the edges of my volume (it seems to be like 16 cubed boxes of voxels reminding me of compression.) - screen attached. Screenshot_50 has about the look I want to achieve, but with this weird halo. When I amp up the emission, the boxes become apparent.Not sure if I tried switching to VDB to render, but I'm not hopeful that would change much.Has anyone come across this issue before?Attached is also my hipfile with the way I set up my render and one cached frame so you don't have to sim again. (Including my approach to an indoor-explosion for anyone who might learn something from that - please do!)I would really appreciate any thoughts on this. (And if my decision to move away from mantra in this case is actually remotely sensible - I'm really unsure.)Thanks,Martin Grenade_RnD_v20.hip
  7. Hello! just wondering what's the best way to gradually decrease the amount of fluid emitted by an object...is there any way of multiply the emission volume by a noise that slowly goes to 0 in amplitude?
  8. Hi, Silly question, but I'm using "old pops" and I just want to simply emit some particles when a point dies(not using collisions) and then create a small burst around the death event of each point dying. Any help would be appreciated as I'm a total noob with expressions/wrangles etc.
  9. Mantra shader emission issue

    Hi, It seems i cannot get the emission to work anymore when using a mantra shader or a material shader builder. The object doesn't light up nor illuminate other object. It works fine with principled shader tho. The project i am working on needs object to evolve thru attributes from emitive to refractive If anyone has a tip or a work around it would be apreciated Thank
  10. Hi guys. I'm doing some tests using shader light emission based on Niels Prayer SciFi Fractal tutorial. But when I pull the values up and use just shader light emission with no other lights I see a lot of noise. I can increase the pixel samples but it increases a lot the render time. I would like to know if its possible to just increase emission light samples to keep pixel samples moderate. Thanks Myke
  11. How would I simply stop my smoke from emitting completely on a certain frame? I'm using Houdini 13 Thanks
  12. Hey, Was playing with 'emiting' packed primitives with bullet, and came across a strange problem. If just have the emitting object on his own, the sim works just fine, but when i add an extra object to the sim, the whole thing just acts strange and add extra geo that shouldnt be there, and that doenst shouw on the geometry spreadsheet. I'm sure i'm doing something wrong but cant see what it is. If anyone could help would really appreciate it. Here's the scene file with both versions. Thanks in advance constraints_v01_010_B.hipnc
  13. Ok so here is my dilemma (one of many lately i know... Im very new to Houdini so please bare with me) I am trying to emit smoke from particles but as you can see from my video attachment, it looks as though the smoke is only emitting mostly from SOME particles and not the others, almost like smoke is choosing which particles to emit from and which ones not too. Also the smoke is going to mostly one side instead of equally spreading out. Maybe i forgot to do a step, but from all the tutorials ive watched i feel ive done every step. I feel very stuck I also am posting some pictures of my Location POP settings. As always, any help is greatly appreciated! ParticlesTest_1.mov
  14. Kill Particles on Rest

    Hi everyone, I am trying to create impact dust when a piece of rock hits the ground. To emit particles I used attribute transfer to create the source from which the particles are emitted and everything is fine to this point. However, I would like the particles to stop emitting when the source geometry stops moving and I can't figure out a way to do it without keying the activation value. Thoughts? Please see attached hip file to get a better idea. Thanks. RnD_Impact_Dust.hip
  15. Hello everyone! I'm trying to achieve an effect with the use of Houdini where multiple sheets of paper is being blown out of an mailbox.(Mail and letters to be exact) My plan is to use different layers of 3d sheets to comp together with some live action plates. 1. Some sheets are Rigid and doesn't fold or bend. This effect I've managed to achieve somewhat. I found a hip file by Valerio Di Napoli where Rigid bodies are being emitted with the help of a particle network. By looking through this .hip I managed to understand the workflow somewhat and create my own RBD emitter. Flipbooks of some test simulations ->youtu.be/f2L9kFGgAH4 My .hip file for this simulation is attached to the post.(RBDs_from_particleEmitter_v002.hip) With some tweaking I think this approach could work as letters are quite stiff when they aren't opened and full of bills One problem I have with this Is that I can't seem to use a grid as the instanced geometry. For reasons I can't understand, when I use a grid they just get stuck at the birth point of the particles and doesn't move at all. As of right now I'm using a box scaled down in the Y axis to act as a letter. 2. Now on to my major problem! Some sheets I want to fold and swirl in the air. I would prefer them to interact with each other but its not must. By using a cloth simulation on a grid to create these sheets of paper works quite well and looks pretty good. Since I don't need as many of these type of sheets, only about 10 or so, I'd like to think that the simulation would not be to expensive to preform? (If more sheets are needed I guess doing multiple simulations would be one way of approaching the problem to avoid performance issues.) Now, I thought that the previous method of emitting RBD might be useful when trying to emitting these more dynamic sheets of paper. I was wondering if there is a way to use the same setup but instead of emitting Rigid bodies I want objects simulated as cloth to be emitted. Is this possible? I tried to just replace my RBD Point Object node with a Cloth Object node and the Rigid Body Solver node with a Cloth Solver node in my DOP network but with no success. Attached a second .hip for this (CLOTH_from_ParticleEmitter_v001.hip) trying to achieve something looking like this but emitting the papers from a specific spot. I'm quite new to Houdini and don't really understand all the abbreviations yet so be gentle on me will ya! Haven't really caught up on the scripting part yet either. I would therefore prefer to solve this without much scripting if that is possible. Is there someone out there who got any thoughts on this? Grateful for any help I could get! Sorry for making this post so long. I tried my best to explain this in my limited English. Thanks! RBDs_from_particleEmitter_v002.hip CLOTH_from_ParticleEmitter_v001.hip
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