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Found 298 results

  1. Hello Houdini friends, For upcoming automotive commercial project, UPP Prague is looking for Houdini generalists, with experience creating photoreal CG environments. Ideal candidate should be a resourceful and reliable artist requiring minimum supervision, and able to deliver top quality work within tight deadlines. Your work could range from generating high quality models, textures and look development (Mantra, Redshift), to creating modular, CG environments related Houdini digital assets. This is 4-8 weeks contract, starting mid-November 2020. Due to current restrictions, you need to be able to work remotely (VPN). For more info, please contact dominica.jandova@upp.cz, and include "3d enviro artist" in the subject line. website and showreel: https://www.upp.cz/advertising
  2. I am trying to create watermelon juice splashing out of a watermelon. Kinda struggling with the shader. I'm playing around with IOR and reflections but failing to get that translucent kind of look a juice has. Any help is appreciated. Thank you!
  3. Hi everyone, I'm having a bit of an issue importing Quixel textures, does anybody know a way round this? From the Quixel forums I have looked at, I think this might have something to do with the Quixel texture (jpeg) not being properly converted into a 'rat' format . Any help would be greatly received.
  4. Rendering thin lines Mantra

    Hi all, Recently I have been trying to understand a bit more about rendering. I was trying to achieve something similar with Mantra. My approach from past experience would be running a pop sim and drawing lines out of the particles to create straight trails as the picture shows. I would then volumerasterizeattributes an attribute like curveu which is ramped to control the intensity along the curve. It would essentially create a volume to render in Mantra and then use Micropolygon rendering to render the volume slightly faster than PBR. I would use a pyroshader and would wire the rasterized attribute into the temperature and density to give it some intensityand color. What I can't seem to achieve is these thin lines that are shown on the photo, I end up with a very thick individual lines in the volume regardless how low I push the pscale or how high the point count is. I assumed I needed more subdivisions to prevent the volume from stepping which solved the issue to some degree but took a tool by being a lot heavier in the scene, but I still can't get the thin lines like in the preview. Can someone explain their approach on how they would use POP's and lines to create such result as the picture shows, or just clarify that it is indeed a necessity to push the pointcount quite high and reduce the pscale in volumerasterize as low as my hardware allows. Thanks, C
  5. Mantra render process script

    Hello I want to know process of 3d to 2d. Do you know the location that process mantra script? (Ex) mantra.py)
  6. Hello! Thanks for come here. I want to know process of converting from 3D modeling to 2D with mantra render. (I mean i want see python code or parameter..) because I'd like to get the object's minimum and maximum value of x,y coordinates on Mantra renderer (you can see picture). how can i do?
  7. I have two sets of color data for a single geometry. One is the color that I want the geometry to look like when rendered. The other is black and white and I want to use that to drive opacity on the 'Constant' material that I have applied. I have tried caching the geo with b/w and then using that on 'Get Attribute' node in the shader network. I tried a few settings, but it just turns opacity to 0/black and my geometry isn't visible after rendering. The geometry that I am working on is a polywire output. They are a lot of long and thin cylinders. Each cylinder has a gradient from one end to the other. This gradient is the black and white color that I want to use for opacity. The required output is to have these strand like objects have an opacity gradient. Where one end is invisible and the other is visible. I have the color data that has mapped it as I want. Just need a way to use that data on opacity parameter on the 'Constant' material. So what can I do to achieve the aforementioned output?
  8. hey people! Im having a terrible problem here. Im doing a guided ocean sim, problem is im doing a 0.004 particle separation and meshing. My final mesh is around 4 mil polys and The moment I try to render it with a simple 2k spectrum I get over 50gb in ram usage. Is there a way to reduce the ammount of polies at render time for displacement? I tried the dicing quality and flateness but nothing seems to work I can't even render with with a principled shader and a small scale disp noise. Same problem The camera is a close up, but I get the same problem even with the mesh on 10% of the screen Im using a 64gb setup
  9. Hey guys, I'm facing a problem when I want to render my extended ocean. Mantra crashes during the displacement creation process, and I'm pretty sure it's not an hardware issue (Ryzen 2700X, 64 gb ram). The output mesh is pretty bizarre : I have a surface created under the mesh when it should be flattened and so there should be no surface here : I dont know what's causing this, but I'm pretty sure that this makes mantra crashing everytime. I tried using a grid instead of the mesh and it's working. I think that what's causing this issue is that when I simulated the fluid there was no particle under the collider and so it results in this weird mesh, I'll try to simulate again with a larger particle layer to see if it solves something. Here are the meshing parameters : I can attach the file if needed but as there are heavy caches that needs to be calculated it may bothers when looking for the bug. Cheers,
  10. I'm trying to create rings in mantra that are larger where my scattered points are brighter. I've got a setup that works for that, but what I'm looking for iis for the rings on top of each other and overlap one another. I figure I need to loop over my point cloud one point at a time and then multiply the result on top of each other maybe. I can't seem to figure out how to get a loop that does what I want. I tried to follow the documentation for the point cloud nodes, and it even mentions that a few of them are useful in a loop situation but it's just not working correctly. Is what I'm trying to do even possible. I don't have a lot of experience with mantra. mantra_pc_lookup.hip
  11. ocean extension tiles

    Hi! I have some issues with my first ocean extension. It shows with strange lines and repetitive patterns. I merged two ocean spectrums, add seed on these parameter and even try diferent numbers on downsample that belongs to material builder. Anyone can tell me what's wrong? thanks in advance. ocean_extension.mp4
  12. rendering problems

    Hello, I want to render and export my simulation as a video; however, the first time I tried to render it, it succeeded but I cannot save it as a video, the error statement was shown as the first screenshot; the second time I tried to use mantra and directly render it to disk, but it gave me another warning shown as the second screenshot. Does anyone know how to solve the problem, or what is the best way to export my simulation as a video? Thanks in advance!!
  13. hi, I try to optimize Mantra rendering. This example is about glass object, so try to apply for high sampling and more refract Limit. To do it, I attached render properties from edit parameter interface in a Geometry node, as a screen capture showing. However, a rendering image seems to ignore and nothing reflected by the parameters. So far; - pixel Samples and refract Limit are not working. - Geo Time samples is succeeded to overwrite. I wonder if I am missing something else, or actually we can only overwrite some limited parameters.
  14. Hello, I made a comparison between Arnold and Mantra renderer about vdb motion blur. Mantra works like a charm, but anyone knows why Arnold volume motion blur looks like this??
  15. Hi, i'am trying to instance lights on custom points that were created from geometry, but render doesn't start at all or rendering and loading a lot slower than standard primitive geometry and ram usage incredible high. If anyone can help, I will be very grateful Custom points https://prnt.sc/sz0fcl Grid primitive https://prnt.sc/sz0grm inctance_problem.rar Problem is solved, pls delete this topic
  16. Hi everyone, I'm trying to render vdbs with motion blur using mantra and arnold. With mantra it's working fine, but with arnold the motion blur won't be proper. I made a comparison. You can clearly see, something is not right. It became more obvious when I increased the velocity. The motion blur with mantra is excellent, but with arnold it became a mess. Do you have any idea what is happening here?
  17. Hi. Like my reference image, I used displacement for the green color. (From Shader) (viewport) (render image) 1. How to soften the edges. (The edge naturally?) 2. I want to add noise to the green color once more, like using a lava shader. 3. It's confusing whether I need to do what I want to do in the shader or in the sop. If you do it in the shader... Is there a way to visually check it in sop? I also attach my hip file. Please advise. Thanks in advance. noise_test_dis.hipnc
  18. Hello, everyone! I have a question about shaders. Like in the image ... It should shine like a lava shader. For example ... I want to give a feeling of shining from the inside. It's like seeing inside a ghost's body. I don't know if the explanation is enough, but ... Could you tell me what keyword to search for? Is it just necessary to adjust the transparency of the mantra shader? Thank you.
  19. Mantra Coat IOR

    Hi! I've been trying to replicate something similar to Arnold's coat IOR parameter in Mantra. Ideally I'd like to be able to control how much of a coat layer is visible depending on facing angles without affecting the underlying surface, even if this involves breaking the law of conservation of energy. Any ideas on where I could start? Thanks, Nathan
  20. fresnel in volume shaders

    Hi all, Because of the absence of deep control in the redshift shader, i'm trying to achieve what i want in mantra but dont get how to proceed. I'm trying to apply a fresnel to the density and emission of a volume. I tried just to multiply the density/emission with a fresnel node but of course it cannot be that simple I tried to create a gradient volume, converting it to camera space and feed it in the fresnel but no succes neither.. Any clue?
  21. Can anyone give me advice in rendering my water simulation? PLEASE WATER SURFACE CACHE is flickering for some frames! I attached image of 2 frames, first one is flickering and the other one is not. Just some of this frame has this problem and I have no idea what is wrong with surface cache. I rendered this water surface with glass material, and I've tried render with other material but it was same with flickering. And Surface_cache seemed fine with it's shape. Is it problem with Normal? Please let me know if you have any ideas. THANKS!
  22. Good evening everyone! I learned some lessons and trained at home in Houdini, and tried to make realistic fluids together in vials for honey and chocolate, other types. I looked at pictures on the Internet and carefully studied how to create bubbles, and tried to make mantra materials. but it’s not like photographs of real honey bubbles. I uploaded - a rendering image and a project HIP. Help me how to create materials correctly? hdri.rar honey_colorls.hipnc
  23. Hello! I have a few questions about rendering glass/refractive materials in mantra. I found more documentation for renderers like vray and arnold for getting good looking glass. Obviously the parameters are a bit different, but more or less they are very similar. Take a look at this photo about glass and vray from this articles: https://blog.turbosquid.com/2014/04/21/turbotips-v-ray-material-part-3-refraction/ For purposes of testing, I decided to create a similar scene rather then in my main project. That way I can work in a simpler environment and also upload my .hip here. My first question are: Many documentations/sites have the index of refraction (ior) for glass. The article above reads: "IOR is a very important parameter to set correctly, in order for your material to look believable. Fortunately, these values have been calculated for all sorts of materials, so there’s no need to guess here." It then states the ior of glass is around 1.5, which checks in with most other places. How can you just say the IOR of glass is 1.5? Wouldn't some glass have different IOR values? Especially if the glass is flat vs spherical or warped. If I try to match the ior values, it looks nothing like the vray photo. IOR of 1.5 is way too distorted to look correct. Please note that my sphere has an inside and a outside (thickness). I set the normals correctly. It seems having thickness to my sphere causes the ior to double. If I delete the inside of the sphere, it is less distorted. So I try setting the IOR to a lower value. However, once I do that, the reflection becomes too weak and super grainy. Mind my actual project is more complex and the reflections are soooooo grainy. Even with a pixel sample of 20 and turning up my light samples, its still too grainy and takes too long. So why can't I change the IOR for reflectivity separately from refraction? The manual says its not realistic, but its just not working for me when it is tied together. If you look at my photos below (you can make them bigger by clicking them) you can see that 1.5 distorts it too much. In my real scene, I have a snow globe. Whats in snow globe is distorted so badly with 1.5 you can't even see what it is. As I said, if I turn the refraction down to 1.1 or 1.2, I can barely see the reflections and they are SO GRAINY. I tried turning up pixel samples, reflection/refraction quality, the sampling on the lights, but its still way too grainy. Any thoughts/tips? glass_test.hiplc
  24. It's my first week using the apprentice version (build: 18.0.391) and I am having troubles rendering my files out in mantra. It seems that this problem is not unique but the available solutions are not working for me (like spacing in file paths, firewall issues, etc). I am still going my way through this but been not able to render my builds is really bumming me out since long time. Any leads will be appreciated. Thanks.
  25. Looking for some advice on rendering a smoke/dust sim with a heavy building destruction sim as a holdout using mantra. Without holdouts the smoke takes about an hour or so per frame as expected, but with the holdouts it is taking many hours (up to 6 hour) for some of the heavier frames. I am using packed alembic caches for each of the layers then merging them together and setting as force matte in mantra.