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Found 28 results

  1. Probably the mother of all dumb questions but how do I extrude along a curve properly? I've tried all the options I can think of in the polyextrude node.
  2. I am trying to mimic a rail spline like you would use in Cinema4D. Essentially I would like each point normal to look at the point with the same index on another curve. From what I've found on getting a direction from two vectors is to simply subtract B from A. However, this does not seem to be the case. (See attached file) Is there more to it than simply subtraction? Align_Normal.hip
  3. Hello, I am new to Houdini and learning. I have a task to do for a client, who requires water to flow along curve just like Realflow DSpline. I am using POP Curve Force to achieve the curve flow but not able to get the turbulent motion. I am trying to achieve something similar like the link below: https://vimeo.com/146377194 Thanks Poojan
  4. Hey guys, Kinda Intermediate at Houdini and a recent full time convert from the 3DSMAX/TP world. I have been working on a tool, where the user can easily plug-in curves and generate art direct able particle flow along the input curves. Its about 90% done, and it works great with curves that are not too close to each other or don't intersect each other at too many points. How ever in certain scenarios. like multiple inward spiral curves intersecting each other, since the POPVOP system is based on Particle Cloud Search : - PC Open to look for particles close to the curve points. - Use those points and push them along the length of the curve using the curve tangents. , the particles get attracted towards either curve based on the search radius and no. of search points. This is definitely understandable, on why its happening. But is there any way to lock/tie the particles to specific curves only? The Radius and No. of Points parameters give it a lot of control for most scenarios, but the one mentioned above. Obviously there are a lot more parameters that i have added for dictating the flow behaviour. But the main solution that i can think of is to have the “found” particle only follow the curve and be affected by the parameters along that curve ONLY. Maybe have a POPVOP decide groups for the curves/particles? TLDR; Need to make the particles only flow along the curve it chooses/gets attracted to at the beginning. I have never worked with groups in POPNET, so im pretty much lost. Unfortunately because of my limited knowledge at Houdini i haven't been able to figure out how to achieve this. Would really appreciate some help on this.
  5. Hi all, I'd like to animate the progression of an L-system like curve, similar to how sliding the generation parameter works. I thought the carve SOP would be the best approach but each primitive's U value starts at 0, causing all the curves to draw from the start. Is it possible to modify the U value of a curve, so that each prim can start at the same value of the shared vertex (where it branches), or can I carve by an attribute? One idea is to duplicate the point where the branch splits on any secondary branch, enough times so that it offsets the order of vertices to be in time with the main branch - I will try to implement this in the meantime Attached is an example file to help explain lsystem_carve.hipnc
  6. Hello, I'm new to Houdini. I am trying to get particles to follow a curve and end up filling a bottle but I cannot get the bottle to fill or the curve to work effectively. I've tried a bunch of different things but the closest I've gotten is with these two files. I used an OBJ of a bottle and turned it into a VDB. In the first file (particle_flow_v07) I used a popnet to get particles along with a popcurveforce to flow along a curve into the bottle. It looks like it worked ok but the bottle doesn't fill up all the way. I thought it was because they are particles and not flip particles but was unsure how to convert them to flip particles. In the second file (v13) I tried using a sphere as a flip fluid emitter instead. The particles follow the curve ok, some of them fly off the curve even though I increased the force of it; and the particles that end up in the bottle only fill it to a certain point then they just spill out everywhere. I tried modeling a funnel to get more particles in the bottle but it didnt seem to work. in v13 theres also a torus I was going to try to use as a sink object but I couldnt get it to work correctly. Any help or advice would be very appreciated. EDIT: So I tried a bunch of tests and I still get the strange purple collision box through my ground plane; not to sure what that is; maybe its the particles colliding with the ground plane? The particles flow along the curve beautifully so thank you for the tip about my particle separation. Particles are still leaking though my geometry and I have a bad feeling it's because of the obj I found online but I am still unsure. particle_flow_v13.hipnc Glass Bottle.obj particle_flow_v07.hipnc
  7. is this possible to make this curve with expression ? tnx
  8. Hi guys I'm new here. First of all I wanted to thank you for having such an awesome community. I'm pretty new to houdini, but have learned a lot by lurking on this forum. I would like to create a spiraling curve(like a phone cord) from another curve(not a straight curve). I already saw some other solutions by just making a helix and deform that along the curve. I also saw a solution about making an arc and sweeping that on a curve and later join the pieces together. I was wondering if there would be a more procedural/mathematical way by using the curve and a point vop or point wrangle? Maybe with a cross product and using the point number as a variable to control the twists? Unfortunately my math knowledge is pretty basic. I would be very happy if someone could post a sample.
  9. This gotta be a bug, right? After troubleshooting it, I just can't imagine what I can have missed that would mess it up. So it's probably something I missed. procedural.web.v02.issue.hip EDIT: Seems the dev's added a convert line SOP in H15 that splits a curve/edge into separate prim's - but I would still like to know why the carve SOP doesn't work in this case.
  10. Hey, I'm new to Houdini but really enjoying it's procedural generation modeling workflow. I've seen a lot of tutorials that get geometry by sweeping a flat shape along a curve and then telling it to skin. Is it possible to do something like that with something that branches like the letter T? I don't want to use anything as complex as a an L-system, I just want to be able to take a curve, branch it some how and then skin that. is that possible? is there a way to get similar results?
  11. Hey, could someone help me building this curve in chop ? I need a curve, a noisy curve with a positive slope. I managed to do that with a pulse (set up to get a positive slope) and adding a noise to it. But the final curve I need has to be like this : (never going down)
  12. Hi, probably a beginners question, but I'm baffled. How can I enter "manually" the coordinates of a point on a curve? I've search the forums, and read about how entering them in the spreadsheet was wrong (enter the soft lock mode (whatever that is...)) And read very complicated answer involving python script !!! All I need is very basic : I made a curve now I need to modify the coord of 2 points in Y axis those 2 pts are at 2.39245 and I need them at 2.4 quite easy ! Yet I just can't do it (without some simple math + offset) I need to do that a lot, so I'm looking for a solution without calculations or scripting. Am I missing something ??? (again) Can't I enter the coord manually somewhere? (somewhere else than in the coodinates list of the curve node, where they are all in line and inaccessible) thanks!
  13. Having an issue with a gap in my Popcurveforce node. Using a basic nurbs curve Circle. Sliced Arc seems to give me the best result but I'm still left with a little gap in the Influence Radius. Any ideas why? Thanks guys
  14. I wanna to get the tornado effect with custom velocity points which run around the the curve. You can check the link below https://vimeo.com/55128796 test.hip
  15. Hey everyone, I'm slowly starting to learn Houdini and I've had a bunch of help from the forums so I wanted to give back and share a hip that I just finished. It's not the most complicated thing in the world, but I learned a lot while making it, so maybe it'll help someone else out. Feel free to offer any suggestions/improvements on it (especially when it comes to how I coded the vex in the attr wrangles). Mike mb_bezier_plexus.hiplc
  16. Hi all, I've been trying to come up with a way to animate this https://youtu.be/gbSIBhFwQ4s?t=14s (ignore the high frequency jiggling movement) I have also attached a quite amazing MS paint schematic, but basically the animation is this: Have my DNA object following a curve (probably using the wonderful free tool https://www.orbolt.com/asset/animatrix::pathDeform::1.00) Other objects (histones) must come in and attach to specific points on that DNA. It then must coil up, all the while the histone pieces have to remain on exactly the same spot on the DNA. Finally the whole unit is coiled up nicely. I really do not know what way to approach this. I think I somehow need to get the histone pieces to be constrained by / attached to the curve, but I cannot find a way to do this (the rivet node seems way to cumbersome to be useful in this). Also, I cannot use dynamics :/ I have attached my current hip file which has the model and correctly coiled curve around the model. Any ideas would be most welcome as I'm quite stumped
  17. Hello everyone, I want to create an effect (as shown in picture) where particles are emitted from an animated curve (like sine wave) like for 2 sec and the those particle keep wobbling around that curve. Its like curve is surrounded with those particles but in random fashion like outer radius of a hollow pipe. Any lead in this will be helpful. Thanks in advance.
  18. Hi Actually, I have a question about a rendering hope that I can get a answer for that. so the question is kind a simple, let's say I have to render bunch of objects and also it include curves which is import from maya. the thing is I need render without curves, so that I only get objects render. so Is there any possible way not render only curves but only objects? since I have lots of nodes, so... I can't type every single node into excluded object in Mantra... Thank you! =)
  19. How would you extract the position of an object animated on a curve? I'm trying to make my animation more procedural and easily alterable in future, so a curve for a path seems sensible (?) - but when I pair that in the geometry sop it doesn't actually update the geos translate position, meaningI have nothing to work with. I've tried inspecting in the details view too and there's nothing there so I'm assuming I have to create the attributes myself but where would I get the actual position from if the geo isn't being translated?
  20. Coming from 3DSMAX I'm looking for a way to have a 'hose' connected to and move freely between two animated objects. As a test I have two boxes, between which I have drawn a curve/line. The two boxes I then convert to static rigid bodies, and the curve into a wire. If I use attach wire to surface - the wire then drifts away from the point I attached it to. I've tried changing the strength but it doesn't have any impact other than exploding at higher levels. Could someone point me in the right direction please, as it would be greatly appreciated. I'll have to apologise, I discovered that if I change the constraint type value from soft to hard I appear to get a similar effect, although it doesn't like dynamically stretching?
  21. I have been playing around trying to really pick up the microsolvers and decided I would try and 'push' a fluid along a curve. Here is my attempt which works but I am feeling a different look. Right now the fluid gets pulled and it looses its smoke movement and ends up looking like an animated fog volume that grows along a curve. Ultimately I want to achieve a 'hand of god' look (reference) with a mix of death eater that is pushed along like a channel of wind. I am thinking maybe a base volume the advect pops but I am curious if any of you have some other trickery for doing this with fields and volumes? it would be cool to get some licks of smoke spring off the curve path and dissipate but I am not quite sure the best direction for art direction and control. (I know the shredding and turb are causing the weird swirling. I did that to see if I could force the smoke out of the curve velocity field so it would dissipate and float away) Thanks ahead! VolumeControl.hip VolumeControl.mov
  22. Hi, I have to issue with something that should be relatively easy to do in my mind. There is multiple poly grids in my scene. 4x4 grids aligned next to each other and also merged together. I need to extract curves splice at certain altitudes. When I use the Cookie SOP, followed by Divide and Ends, I always end up with a seam in between each grids. Is there a way to get rid of the seam? Or a better way to make this happen? The goal would be to extract iso lines just like on this image. BUT... I don't need all those lines. Only one line at the height the user desire. http://www.ctech.com/wp-content/uploads/2011/12/isolines-viewer-1.jpg Many thx C
  23. I'm looking to add additional curves into an existing fur system. We're exporting the curves out of houdini and my question where do I merge those additional curves into ?
  24. I am mainly a blender users. I would like to start using Houdini. It's procedural and non-destructive workflow is very appealing to me. For my first day in Houdini I would like to re-create something procedural I did in blender using modifiers. I have a piece of tiling geometry, it is a section of a stone wall. I would like to array this wall along a curve. Also I would like to project the curve onto a piece of terrain. I am not expecting anyone to solve this problem for me. But I wouldn't mind some hints on how to approach this problem.
  25. Is there a simple way of closing an open curve with out creating a renderable/visible surface. After closing the ends I just want to get a simple like the circle on the right. The Ends Sop creates a surface..How can I avoid this? Is placing the first and last points at the same position the only solution? Btw the curve is animated and random pointnum sorting. Can I somehow get for every frame the pointnum of my first and last point so I can push them in the same position?