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Found 64 results

  1. Hello everyone! Even though I've had many help on odforce it's my first time posting. As the title says I'm trying to figure out how you would use particle velocity to increase and decrease the speed of a looping animation. I have done it with a copy stamp but I was wondering if there is any other way around it. Thank you in advance
  2. particle question

    Hi, I found this setup for particle morph: float strength = ch("strength"); float arrivedistance = ch("arrivedistance"); int goalpt = @id % npoints(@OpInput3); vector goalpos = point(2, "P", goalpt); f@goaldistance = distance(goalpos, @P); vector goaldir = normalize(goalpos - @P); @v = goaldir * strength * fit(@goaldistance, 0, arrivedistance, 0, 1); Setup is very nice but it would be super to add functionality. Im new to vex. Is it possible to move particle into the nearest point on the target, because at the moment (I attached screenshots) particles morph in random way (evenly fills the entire object )? It would be perfect to fill object starting from the closest point. I will be very grateful for your help. Regards, Pawel
  3. I have a collision object that I want to push through a particle sim area. I want to remain the small sim area (box) so the particles stay inside the tight area but once it gets hit by the collision object the particles that were affected by the object fly off. How can I achieve this? Thank you, this is the file I am talking about. Particle Collision Tester v03.hip
  4. Test destruction

    My work for January - February 2018. These are tests on destruction of 16 Houdini. I ask for your opinion on quality
  5. hi everyone, i am trying to slide particles in the inside of a geometry (a polygon box in this case) i want to get the particles freely slide along the walls (or even come on and off the walls because of the popattract force), which i managed to do with the two nodes popcollisiondetect and popproperty, however it doesn't quite slide... it goes past outside the box. especially if i increase the popforce amplitude. to keep them sliding (and inside the box) i have to raise the "cling" in popproperty node to very high value which almost makes them look stick rather than slide. However, a sphere instead of a box works fine.... the pighead somewhere in between the box and the sphere. anyone knows where i should tweak things? FYI the settings for dopnetwork is same for all the three images (1a,1b,1c) I would appreciate any help. PS: BTW how do i i make the quality of a simulation more precise (increase steps per frame) globally. m.
  6. Random shooting box

    Hi guys , I'm totally beginner of houdini and I'm stucked with some problems. I set up boxes randomly in scenes, and want them to shoot at same direction. I mean, some box goes to X-axis at 3 sec, and some start to go at 6 sec like that. Here is example, I want to shoot boxes randomly to blue arrow direction. But I don't know How do I deal with Id(?) or that boxes point numbers T_T Please help me !
  7. Hi gang, I was just scratching my head over how to get my popaxisforce object to follow the emitter I want to affect with it. It's basically a geo group that defines the emitter surface (jet engine thing) and shoots out particles behind it and I want the popaxis force to follow close behind to manipulate the particles. I thought maybe object merge in the dop network would do the trick but it's doing some pretty weird stuff instead like creating a duplicate emitter that follows the jet's animation/xform but offset in time. Any insight would be great, thanks! jet_emitter_popaxisforce.hiplc
  8. I emitted particles and I want to make them stopped where I want. To solve this, I emitt particles and use popgroup node(Bounding and use Bounding Object). when they are into bounding box, group:groupname attribute become 1 and I made pop wrangle behind the node and wanted to make their velocity to 0 But How could I control that group:groupname attribute ?? and If I solve that, particles will be stopped and make a line. but I want to make them spread in the bounding box... Please help me.. sorry about my poor English thank you for read
  9. Hi guys, I made several text by font node and I want to pop out them randomly. I thought about that make some variable to each of them like 1,2,3 and rondomly selecting in wrangle node. but I have really poor logical thinking and It is taking lots of time. Help me with it plz ! Have a good day and sorry for my poor english too :S
  10. Particle blow effect?

    Hey magicians, Just saw this fantastic spot by Lewis Orton and I was wondering how to achieve this effect where the particles are calm and explode up (sec 0:9 and 0:22), I tried with a ripple sop to drive the particles but the effect is very poor (and particles go up and down instead of up only, tried vector to float here with no luck) Any tip to get me on direction will be really helpful! Thanks!
  11. Hello Pals, Hope you all are having a great year so far. I am trying to do a shot with particles which needs slow motion on a certain camera moment. Basically, I just want to slow down the motion of my particles for few frames. I dont want to mess with the velocity etc as I really like the motion of my sim. I looked into time-shift, time-warp etc. But they always feel like a cheat and not much of a high quality solution. There is a "Scale Time" option on the POP net. But for some odd reason its locked and we cant key-frame it at all. That would have been the best solution, where we can just lower the timescale for bunch of frames and then resume it in normal speed. Can anyone just give me a brief why Sidefx would want to make this such a big deal and lock it on POP nets? Thank-you and have a great day! HD
  12. Hi, during the work with my maya alembic reader, I discovered a problem with alembic files written by houdini. Obviously Houdini exports an additional point geometry together with my mesh. If I load the alembic in Maya, I get a mesh shape and a particle shape. In houdini I can see two packed objects in the alembic sop. This only happens in certain situations. e.g. if I create a box and deform it, only one packed object is created in the alebic export. Only if I export my flip mesh an additional packed point geometry is exported and I get a warning in the exporter: "Renaming node to /geo1/file3_1 to resolve collision". Does anyone know what's going on here? It seems not to be a new phenomenon, it happens the same way with H16.
  13. Hi, I'm trying to replicate the way you can set color for a particle's "initial state" in a Maya particle system. I've looked through docs, tuts, etc, and have not been able to get this to work: Here's what I got so far: ---------------------------- I've scattered points over some terrain Geo, used a point Vop to create noise based color for the Cd attribute on the points, then used the points as the initial geometry in the popObject. The idea is to have textured "dust" blow over the Geo (I'm driving the pop animation with a Pyro sim). The animation works well, but I can't figure out how to transfer the Cd attribute of the scattered points to the particles. I played with creating the color with a PopVop in the Dop network, but the color is assigned by position so the particles animate but the color does not. I've attached my test scene. I'd appreciate any clues; thanks in advance bcs_partDustTest_v01.zip
  14. I have a popnet creating some particles with the POP spin, to have a random rotation in each particle, also Im copying a tube in each particle, the tube rotates as it supposed to, but when they hit the ground, the tubes stays with a random rotation as well instead of pointing Y. I'm thinking that if I use the normals instead of the POP spin I could blend between the N0 and N1 when the particle hit the ground, using the hit info from the POPnet, but truthfully I don't know how to achieve this .-. I'm using POPs and copy the tubes/coins to the particles because the particles born magicaly from the floor after a character hit the floor with his cane. If anyone could help me or have any idea I would appreciate it!!!
  15. Delete particle

    Hi, I'm a student learning houdini. I'm working with particles and I want to delete just few of the points that I choose. I tried to use particle ID but because of the life expectancy variance, the id keeps changing and I couldn't delete the point. So, for the same reason delete SOP doesn't work too. (It only gets deleted in the specific frame which I selected the point) Are there any resolutions of deleting particles that I want to delete? I've also seen an example hip file in odforce that uses 'for loop node' in VOP but I couldn't try that way because it doesn't work in houdini 16.
  16. Particle rotate based in friction

    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
  17. Hello guys, i have a serious mesh flickering problem in my flip simulation. The timescale in the flip solver has been animated to slow down the simulation. Looking at the particles everything seems fine, but when it comes to meshing and the particles are moving really slow, the mesh starts to flicker and holes are forming and disappearing every frame. I've tried increasing the resolution, lowering the particle separation in the particle fluid surface node (or vdb from particle fluid, i've tried that as well), lowering the grid scale or the particle radius scale, the flickering changes but it never goes away. any help is greatly appreciated thanks in advance slowmoving_flip_flicker.hip
  18. Hey all, I'm a compositing student but for a current group project we are to make a bumper and ended on doing it in Houdini because it just looks best. So I don't have much experience in Houdini before this except watching some courses/tutorials and playing around very little. The learning curve is quite steep and I've run into several snags. First of all I followed this tutorial to get the first morph/transition and things panned out pretty well. However I got a third model and maybe even a fourth and I don't know how to add these into the mix. In my current file there is just a simple blendshapes for the third model but it's quite uninteresting. That's it for starters at least. Other than that I'm trying to figure out how to change the colors between each model as well. The project file is probably pretty dank since it's my first project in Houdini. I really love the program and want to continue working in it! Hopefully someone out there could take some time to look it over and give some input. Attached is a .rar with .hip and the .fbx camera as well as x3 .obj models used. bumper.rar
  19. Particle effect help

    Hello magicians, I'm stuck in a R&D for a client, been trying to do a particle behavior for 5 days without success. Heres a video gif of the latest client ref: http://i.imgur.com/dvtTkL1.gifv Also attached is some early image references the client sent but I would like to focus on the gif one. Here is a gif with some of my RDs, I tried advecting particles from pyro, doing a pop network with curve forces and some more stuff, the behavior the client wants is some sort of flock/swarm like a monster that chase a person. http://i.imgur.com/Bs9kFbK.gifv Thanks in advance Cheers!
  20. Particle scale

    Question about particle scale. All I did was create a location particle emitter. Then I converted the particles using the vdb from particles. Here is the question: What is the best way to control the scale of each particle, and what is determining the scale it is outputting to the vdb node? See how big the particles appear to be in the vdb picture? Thanks
  21. Particles collide inside a mesh

    Hello everyone,Sorry for the basic question but I just want to emit some bouncing balls inside a mesh with Houdini 15.5. To create that I just create a source particle emitter and I put it inside my collider mesh. I make the mesh a static object and increase the uniform division and click on invert sign in the static object node. But when I launch the simulation the particles have a very strange behavior. If anyone have some idea to achieve this.Thank you for your response. animation_particles_gpe_v003.hip
  22. Hi everyone, I'm an extreme beginner when it comes to Houdini, can someone please tell me how to make some falling particles more bouncy when they come into contact with a ground plane? Thanks!! I've attached the file Ball Pit Ball Simulation 011.hipnc
  23. Audio affecting particle position

    Hey all I'm quite new to houdini so please bare with me. Is there a way to use an audio output from chops to change the position of a particles? Can I do that by using a pop vop? If so, how can I import my chops output in there and add it to the position of my particles? Is there maybe a better solution for that? Thank you!
  24. fill mocap volume

    Hi all, I'm working with some mocap meshes that I'm trailing particles over using the 'minpos' technique in POP VOPs. I'm getting a little stuck though, as when i make trails of the particles, these obviously trail behind the mocap as the keep their birth XYZ coords. What I'd like to achieve is that the trails adhere to the surface of the body/geo in the same way that the particles do, so i end up with something like 0:24 > 0:26 of the attached video. Maybe I need to do something within a sop solver? perhaps dop pop is the completely incorrect way to go? Any hints or tips greatly appreciated - I've attached my .hip here should anyone have the time to take a look! Thanks! (hints on filling the volume as-in the video will also be met with rapturous thanks... I'm not even sure where to start with that one.) surface_particles_trail_test.hip
  25. Particle Explosion

    Hey, I can't figure out how to emit particles in all directions from geometry. I mean, when you emit from geometry it does go in all directions, but how do you multiply that speed? I messed with particle variance, and it seems to work except for the fact that turning it up moves the particle on the first frame. In maya, there is "away from center". I turn that up, and particles shoot from the center outwards. How do I do that here? Thanks