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Found 88 results

  1. Hello, The effect I'm trying to create is a dragon fire effect, However since I've added new translation to the particle emitter and and container the simulation no longer runs correctly. I believe this is to do with the individual DOP networks yet I'm not sure. Any help would be great since I've been stuck on this issue for some time Thank you Dragon_flames11.hipnc
  2. Hi there, I'm trying to control flip particle count per voxel. The idea is to evaluate particle count per voxel on every step (Gas Particle Count) and then analyze the pcount field.. If pcount > n - delete some of particles (pcount - n) to make n numbers. And if pcount < n - add (n-pcount) particles. Any help is highly appreciated. Thanks,
  3. Hi guys I have a question that is breaking my headoff. I have a simple set up, I have a ground to collide and is scattering points in the surface , based in the distance threshold of an animated geo, I created a group based in an attribute, also have the N and v set up. From this group I'm creating particles to simulate some kind of debri left behind of the falling "rock". The particles when are born they rotate until they hit the ground, but not when are falling or "sliding" in the surface of the ground. I have a POPGraings that give me this nice falling/sliding look. Any idea on how to get the particles rotate based on the friction or contact with the ground surface? Thanks for any idea you can give me
  4. Hi guys I have a question that is breaking my headoff. I have a simple set up, I have a ground to collide and is scattering points in the surface , based in the distance threshold of an animated geo, I created a group based in an attribute, also have the N and v set up. From this group I'm creating particles to simulate some kind of debri left behind of the falling "rock". The particles when are born they rotate until they hit the ground, but not when are falling or "sliding" in the surface of the ground. I have a POPGraings that give me this nice falling/sliding look. Any idea on how to get the particles rotate based on the friction or contact with the ground surface? Thanks for any idea you can give me
  5. Hey. I have a problem with overwriting values from wire object in SOP Solver. If klinear parameter (Linear Spring Constant) is set to 300 in wire object and then I'm writing inside sopsolver in point wrangle @klinear = 300; just for test, then my simulation looks different, less stabile (?). Why is that happening? This is the same value so it should be the same sim. I was trying to put sopsolver before and after the wire solver and there was the same situation.
  6. Hi, (Sorry if this kind of question was asked before) I'd like to set up a flip fluid in a fashion similar to naiad's, where the particle density can be set up separately for the surface and the volume of the fluid. (See attached image as an example) Now, the generation of this is pretty obvious, but I'd like the flip solver to behave as if the in-volume particles had a bigger scale or radius (so I'd need less particles to fill the same space). I tried to adjust the pscale attribute of the inner particles, but that doesn't seem to affect the solver. Any ideas would be appreciated... imre
  7. I'm scratching my head over this issue. My FEM object is slipping through the animated Static Object slowly as it spins. The Static Object is set to "Use Deforming Geometry" and does not act as expected. FEM_slipping_through_StaticObject_slowly.hipnc
  8. Hi, I'm wondering how to go about creating a static shape of a stretched cloth/rubber sheet. Something like this: I've got an overly complicated version working where a set of points are constrained to primitives belonging to another geo but I suspect there is a way define pinned points and everything else is under some stretched force? Maybe initial state or rest geo is just a smaller version of itself? Thanks heaps!
  9. Volume convolution on the GPU using OpenCL. For 27M voxels using 100 iterations, OpenCL is 650 times faster than C++ and 12525 times faster than VEX.
  10. 【i'm not good at english】 there are some attribute on particals in dop, i want to transfer these attribute to other points that particals hit on in geo . How to do this? Please tell me the core node, or give me a exmple. Thanks. 【i'm chinese ,so you can ignore the following content】 怎么让dop里粒子的属性,传递到geo里的模型上?原谅我是新手…… 求主要节点,或者例子
  11. Hello everyone, so we finally got the full FX license for Houdini and I merrily went about rebuilding a setup that I built in the apprentice version, some FLIP shenanigans. The apprentice version wouldn't simulate when I enabled checkpoints, I thought that was so you can't simulate in apprentice and use the cache in the full version. But now I've got the paid license and the problem persists. I set up the checkpoint file name but no matter what interval or trail length I set, all it ever does is simulate frame 1 and write it to disk, then stop simulating the DOP network, showing me memory cache blue in the playbar and just playing the animation. I'm stumped. Is there anything I'm missing or is it a bug in H16? Any help is appreciated. Thanks in advance Paul
  12. Hello, I'm trying to get a logo to dissolve/disintegrate into sand. Like it is made out of sand and something is eating out the outside shell and the sand is pouring out. In the attached file I was first trying to use a geometry and use attribute transfer to set the force of a popforce. as I would like to use in the future a more random/noisy pattern. I'm not exactly sure if my expression is wrong, if my whole set up is wrong. I tried to look around for tutorials or thread but couldn't find any. Any idea, suggestion or links would be greatly appreciated. thanks bil Sand_Desintegration01.hipnc
  13. I am struggling to architect what I have in mind and it may be quite simple but... somehow I just don't get how to connect the dots. Attached is a file with a fractured sphere (thin shell) and a small obstacle inside moving fast, I want to break/weaken the glue constraint based on the impact data (may be after a certain force of impact. At the moment the sphere gets moved around by the obstacle, instead the sphere should break on contact with the bullet, but not against the floor. Thanks in advance. PS. All the elements inside the attached scene are using the shelf tools, specially confusing is the ImpactAnalysis. impact_glue_interaction.hip
  14. I want to create a digital asset where I need to simulate pieces of a fractured object falling down to the ground to get a plausible initial "lying-on-the-ground" orientation for further processing. Is it somehow possible to simulate until a certain condition is met (for example all pieces are frozen) and then fetch that state as an object merge or something like that? I am sure this is possible with python, but I'd rather take an approach that relies on the SOP dependency analysis alone if thats possible. Any hints would be very appreciated!
  15. Hi guys, I've hit a bit of a wall in the new version of POPs. I have a deforming mesh (skinned character), which I have scattered points on. What I'm trying to achieve is a set of particles that are essentially locked onto their source point until a certain time or proximity from some sort of gizmo, and then morph to the position of another set of points. I have been able to achieve this in the old version of POPs using a position node, but it's rather slow. However I can't seem to figure out how to achieve the same thing in the DOP version of POPS. Any help would be great appreciated. Thanks
  16. I have replaced the file with just a cube so you guys can still see what is going on. It's very basic. It's just a box with points at the center of each piece telling what is active and what is not active. however when I put this expression: point("/obj/Angel/AC", groupbyvals("/obj/Angel/AC", D_POINT, "name", $OBJNAME), "ACTIVE", 0) in the active value DOP that I got from another dude on a forum on here, that expression doesn't work. Can someone please tell me what I am doing wrong here? This is for a demo reel project so I am on a time crunch..that's why I'm posting this. Thanks so much!! Angel_Destruction_3.hip
  17. Hi Houdini friends, Does anyone know how to use mask field in DOP net? I'm doing a simulation of leaves on the ground reacting to a car passing by. I need to control the wind force to affect only where the car is passing, where other leaves remains more still. Is there any way to mask out the affected area and have the wind force only affect that area and have dynamic change on the mask object? Or if there's other ways to do this? Thank you so much!!!
  18. hello all, is somebody has solved problem like this, when i substepping the simulation into 10 substep on the dopnetwork, then setup the step playback frame into 0.1, then i write the cache with step 0.1, i got error number sequence. i had try with freeware for batching rename, but still didnt get the patern number because every 10 frame, the lenght of the filename was difference. its okay if the range under 100 framets but my frame above 3000 fame, its paintfully if i manualy rename the file. is there anyone ever had solve this case? thanks all.
  19. Hi Houdini friends, Sorry to bother you three times in a day... I'm still having issues with the simulation of leaves on the ground. I can't use POP for simulation because these leaves are in foreground and they'll hit the ground and stay eventually. However it seems wrangle torque or angular velocity on the packed points won't work, these leaves are not spinning around their own origin. Is there any way to fix this? I have the files attached that may better explain. Thanks a lot!!!
  20. Hi houdini friends, Is there a way to deactivate the force when it's not in the mask field? Right now I'm doing a scene where leaves rise when a car pass them. I tried to use the mask field to mask out the area that should be affected when the car come, but as the car goes by those affected leaves seem to be still affected by the wind force, but they should fall down eventually. Does anyone know the solution to this? Thank you so much!!!
  21. Hello everyone, I used to cache multiple alembic using the technique described here : http://nicholaspfeiffer.com/blog/2016/1/16/houdini-tip-of-the-day-render-multiple-alembic-rops-at-one-time (Long story short : rop network > multiple fetch > a merge > click render > caches every fetch. That's cool !). I thought that it would work the same way if I use this technique to render multiple Dop I/O node. For the first time I want to use the take system to cache multiple sim over the night (changing resolution and parameters). So in an obj node I dropped 2 Dop I/O, set their "Render With Take" parameter on each one, then dropped a Rop Network, two "Fetch" nodes and set their path to the dop I/O "render", dropped a merge, and hit "render". The result expected would be to have the different takes cached but instead I had the Main take cached, two times... What do I do wrong ? Thanks for the help, if a scene is needed I will do a simple version of it Have a great day/night !
  22. https://vimeo.com/188376689 Hi guys, I posted this on the SideFx forums but I also wanted to share it here... Basically, after the webinar on particles I felt inspired on creating my own galaxy system. The objective I put my self was to create a space opera style looking galaxy. But the real aim was to create the working forces behind it. Basically a system that can define the sun or suns, the initial speed of the traveling space objects and the gravitational pull forces affecting all of them. Also I added a particle absorb relationship, some big particles will gradually absorb the mass and size of the smaller ones, making themselfs more massive and bigger. I feel there are some quirks to polish but overall the core of the system is already there. Everything is based on real physics, or as close as I could get without making it super heavy. And indeed the results varies dramatically (in a good way) acording to the parameters input on to the forces, basically mass of the sun, of the debris around, distances, and initial speed. It was a fun excersice! maybe I will revisit it one day.
  23. Hello! I'm quite new to Houdini - still trying to grasp some concepts. I need to create falling leaves simulation. I have been trying out different ideas but have some questions: 1. Is it possible to have normal/tangential drag (like in cloth objects) for RBD objects - to have some sort of aerodynamic effect ? I would like to use RBD to simulate a lot of leaves faster as I don't need soft deformations. Cloth sim gives very natural falling motion with normal drag active, but is very very slow for several thousand leaves. 2. I am creating my geometry using simple copy on scattered points and then doing Assemble to create individual leaf names. Partition to group them by name. Then feeding it all to DOP. The question is - what would be the best approach if I want to remove from simulation all the leaves which have reached certain condition - i.e. they have collided with the ground (or some other condition - i.e. leaf velocity is 0 for last N frames (For cloth it would be average velocity of all leaf points)). I need to keep the geometry around and render it, but I would like to remove it from Cloth/RBD simulation to speed things up. How are this kind of problems usually solved? Is it possible to remove objects/pieces from dynamic simulations?
  24. Hi everybody, I'm currently working on an effect in H14. I am attempting to have particles die when they collide with an SDF/VDB object. I have been using the collision detect node with the collision target set to DOP objects pointing to my static object collision node. However, it doesn't look like it works. The same collision detect does work with a SOP poly object. Is the collision detect node working with SDF's/VDB's? Cheers.
  25. Hi everyone I applied a cone twist constrain to an obj, and then when i'm trying my sim I can't play in the right way with the parameters. everything I touch my fracture just "bounce" instrad of breaking. I tried to change also the Physical parameters of the object, why this is not working? Thank you