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Everything posted by bigwil357

  1. Hello! I was wondering how you make 2 pyro sims interact with each other. Mainly taking the force of one sim, and having it affect the other. For example, a Flame thrower as the first pyro sim, then it interacts with a floor dust sim, and the velocity from the flame thrower moves the ground dust. I understand that the velocity from the flamethrower can be used in the other pyro sim, but i dont know how this is done. Up until now i have only worked with once source, with once container. Not sure how this works. Any help is appreciated!
  2. Rendering pyro with volume lights

    Thank you so much! This helps alot!
  3. Hello! I have a Pyro Fire sim with smoke, on a house which is 100 frames. The pryo sim is 100 frames, with a static camera. A volume light is on my fire, and the light from the fire reflects on the house as expected. I also have an environment light for over all lighting. My questions are; -How do I render out the fire & the smoke? Should i render them out together (Which i know how to do), or separately. And if separately, then how do i split the two simulations? I also have some of the fire light scattering on the smoke & i have rendered out a fire and smoke mask as well, if that makes any difference. -The other question is, since my camera is static, i should only need one frame for the house lit by the environment light. Can i render out the volume light pass from the fire separately, so i dont have to render it all with the house? Thanks in advance!
  4. House fire sourcing Pyro

    I appreciate the replies! Im not sure i understand whats going on in that file. Why do the particles point away from the windows, but the fire goes towards the windows? The particle sim, is very small compared to the pyro sim. Why does it still work? And what is controlling the direction of the fire? Im pretty much starting with 17.5, so could that be the issue? Things look alot different. When it comes to smoke, should i emit from the fire, or just create another sim that just emits smoke? And if i want to control the smoke, from the fire, is there a way i could do that without changing the fire sim? Maybe im wrong, but it looks like when smoke is being created from the fire, that the settings control everything. There is no separate set of parameters that only control the motion/shape of the smoke, and leave the fire alone. Also im more looking for how to start the fire. Id like to know how this would be done "professionally". Like would the source come from the geometry of the building? Source from the window glass? Put geo on the floor, like a campfire, and go from there? Is that the correct way to start this, or if a deformed sphere like i already have work for my needs?
  5. House fire sourcing Pyro

    Hello! I am trying to achieve an effect of fire coming from a window. I am unsure how to approach this. The goal is to have a flame that comes out of the window, and smoke drifts slightly to the left. Currently i have a deformed sphere, as my source geo. It looks ok, but i feel like there might be a better way. Any suggestions are appreciated. https://www.youtube.com/watch?v=SAh92E4UMFw Reference at 3:00 https://youtu.be/s-UOhgKVtQs?t=179
  6. RBD Material Fracture Door hinges and constraints

    Hey guys. Still working with the sim. Ive given up on the door hinges. At this point, i am just trying to have a decent simulation. 3+ months, and this is what i have come up with. Learned about constraining 2 objects together, which seems to work, but things still are not working as i expect them to. When i try to use the Point Wrangle in the SOP Solver, i just dont feel like its working, so i switched to animating the constraints with the DOP geometry. I would rather have the constraints break by torque, angle, etc but it just dosent seem to work for me. Another issue is whats the best force to break there objects? Ive used sphere geo, and now metaballs. Does one give a more "explosive" look than the other? Lastly is how to get the pieces to just settle after the sim. Some sims are more stable than others, but i dont know why. Ive played with the substeps and collision padding, but still get issues. Any help would be appreciated. Ive learned a TON, but still cant seem to pull off a simple sim. File attatched. House geo is in previous attatchment LostHouseCON2v4.hip
  7. Hello. Ive been struggling with this scene for a while and ive exhausted myself trying to figure this out. I would like to make a door explode, and leave some of the fractured door swing on its hinge. I would possibly like to destroy the rest of the house later. Ive been self studying for a while, and i understand how the constraint network in dops works, how glue and soft constraints work, but im unsure how to approach this effect. I think im doing the right thing in SOPS, but im not getting the results that i want. I understand adding the active attribute to the featured geometry to make an inactive area as well. I would like to do do somethging similat to this video with the door swinging by the hinge, as the remained of the door remains fractured. Look here https://www.sidefx.com/products/houdini/whats-new-17_5/ the video is at the "interactive RBD constraint" section. Some of my issues are; Why does the geometry fall when the sim starts? I understand that Glue is on/off, but i still have it fall once the sim starts. (not including the inactive area) How to constrain two objects? If i would like the wood frame to be glued to the wall, how can i do this? Is it just a matter of drawing lines (RBD constraints from lines) to connect the objects together? Ive also tried using geometry as constraints, with 0 luck as well. Should i just use an animated bounding box to make the area "active", and then have the sphere break the door? Or is there a way to have the door break, only where the sphere collides with it? I am familiar with DMM in maya, and im not sure if animating a passive/active region is the way to go, or is there a better method? Odforce_hinge_scene_zipped.zip
  8. RBD Material Fracture Door hinges and constraints

    Thanks you very much for your reply! I actually used the help docs to create that scene. guess i still have alot to learn. I had no idea that using packed geometry was the issue. Its seems like i always see people using the RBD packed object, so using the RBD fracture node was new to me. But why is this? Is it because im using constraints generated by the RBD fracture material? Also when it comes to naming constraints, i dont have to use a wrangle node and manually type them in, right? I thought that the RBD constraint properties node took care of all of that. And i also was under the impression that if you have the same constraint name, in SOPS and DOPS that everything should work fine. One thing i am curious about is why and when do you delete the channels on the Overwrite with SOP parameter in the Constraint Network node in dops? Do you do this every time you use a SOP Solver, or is it only used in specific instances?
  9. Letter Rising from Sand/grains COLLISION issues

    Thank you so much for your reply! I believed that i figured out the issue! I had NO IDEA about the open CL stuff. Theres a ton to learn in this amazing program, and i look forward to creating more! Thanks again!
  10. Hello! I have recently been offered my FIRST FX job! I am familiar with Maya, and some Max, but this job requires that i use Houdini, so now i am all in! VERY EXCITED!!! I have a scene where i have to make some letters rise from sand. The issue is that i cannot get things to collide correctly. Doing my research i have tried using it as a RBD object, and using a trail sop to computer its velocity, but i still dont see any collisions. I use static object, pointing to a VDB smooth as the proxy geo, and all of the collision detection/mode set to volume, but no collisions still. I set the sim up with an initial state file too. Could that be the issue? When i take away the VDB to polygons and VDB smooth, delete and just run the sim as a regular static object, everything works! But...i get some weird artifacts rendering. What is the best approach to this method in Houdini? Im sure the solution is just a setting away, but im lost here. Any suggestions? LetterSetup_001_collProbs.hip
  11. source flip fluid with velocity

    Did you ever figure it out? I was playing with this too, and couldn't get tit to work either. Trying to get that directional emmiter effect!
  12. Letter Rising from Sand/grains COLLISION issues

    So i just realizes that the artifacts are coming from the rising letter, reacting to the groundplane, stretching over it. It pishes the groundplane up, like its cloth. Is this correct? Do i need to figure out how to stop the letter from colliding with the plane, or is this correct, and i just have to hide the groundplane geo? I didnt even know that was possible!
  13. I have a scene where i need a bunch of objects (arrows), to follow each other. For some They need to follow a rigid path (think steps) where they would go, lets say move 10 units in x, 15 units in y, and then 10 units again in x. At other times they will need to have a more organic path. Kind of like an S shape. Im not sure how to approach this. If there was a way to draw a path with a spline curve, and have objects, or instanced objects be birthed, and the begening of the curve, and die at the end, that would be ideal. I know i could keyframe animate the arrows, but that seems tedious, and feels like its the long hard way to do things in this situation. The scene needs to be able to work in Maya as well. Can anyone help?
  14. Expression question

    Hello. Im not sure exactly how to make an expression for this type of animation. I have alot of objects that need to separate from each other, rotate 360 for a certain amount of frames ( ex. frame 50-100) stop rotation at it original position at 0, and then I will hand animated them back to their original position. My question is how to set this up? I can do it by hand, but I know that is not the right way. I think I did something like this with an IF expression a long time ago, but i cant remember. And its such a simple question that it is hard to find an answer for it.
  15. TimeLine dead zone

    So I am doing some Animation and I have several nodes selected. I have extended the timeline and I can animate my camera with no problem. But there is this area on the timeline where If I put any keyframes on it, nothing happens. In this dark grey stretch, nothing happens, and the Parameters turn blue. How can I fix this? http://tinypic.com/view.php?pic=6rpnr9&s=8#.VDIXOfldXmc
  16. TimeLine dead zone

    So I havent even put any expressions on the geometry, just keyframes. I dont understand where it came from. In my graph editor there are no keyframes either. I just want to get rid of it, without having to do the animation all over again. I will if I have to, but I would rather figure out the problem now, in case I have this issue again.
  17. Hello . I have imported some OBJ's into Houdini. They have been slightly manipulated, and then I write them out as .iges files. The problem is that when I import the files into the other program,it is missing all of the shader data. Is there a way to save it all at once?
  18. Hello! I am having an issue with Exporting OBJ's to .IGES or IGS file format. I usually try to work solely inside Houdini, and I have actually never had the need to export anything. I usually just lay around with Pyro. Now that I need to for a job I am having quite a delima. I have been given .obj files of a car window(s). I import the file directly from the file menu. The files actually have 4 different windows, but it just comes in as one mesh. In modo, I have the choice to import the file as 4 different meshes, In houdini i do not see this option. anyways... I then select the primitives on the windows that I dont want and delete them (dissolve because I cannot select them as individual meshes) Make a file node, right click on save geometry, and then Nothing. What am I doing wrong? How do I export these files? I have tried to look everywhere before I created this forum. Any help?
  19. Exporting OBJs to .IGS or .IGES

    Ive got it to export. It turns out that I had to have $HIP/ in the output file name before the name of the object to export it. I sent it to the client,and they said it worked well, but there is no shading information on the object. Any ideas?