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Found 33 results

  1. CHOP's Frame limit

    I am in the process of setting up several camera rigs following the same piece of geometry with lagged "look at" constraints. The lagged Nulls I have made the camera "look at" only behave as they should up until frame 240, after which they stop moving completely, despite the scene length being 1000 frames. I have attached the .hip file, any suggestions are much appreciated. Thanks! CHOPsBug.hipnc
  2. I have an animation channel with keyframes with various integer values. In CHOPs, I'd like to have a rolling counter that holds the sum of values on all preceding keyframes (values from keyframes only, not values from all preceding frames). Any idea how to do this? Below is a sample of what the counter would do: Keyframe on frame 1: value 3, counter: 3 (3) Keyframe on frame 8: value 8, counter: 11 (i.e 3+8) Keyframe on frame 13: value 4, counter:15 (i.e 3+8+4) Keyframe on frame 23: value 4, counter:19 (i.e 3+8+4+4) Keyframe on frame 29: value 7, counter: 26 (i.e 3+8+4+4+7)
  3. I am trying to re-create a ribbon deformer in houdini that takes transformation and rotation data and, using interpolated values transforms a bone chain. I have linked controls to a surface, and extracted a line from that surface with what I think is the required data. I am not sure how to take that data from a geometry level and apply it to a bone chain. I assume chops is the way to go but I don't have any experience with them.
  4. Hi everyone, I'm trying to create a delay effector style effect on some copied boxes, but I've chosen the option to pack primitives before copying and now in CHOPS I want to know how to make say a Spring CHOP pick up the rotation of a packed prim. Here is an example scene file below. Thanks to anyone who can help. C4D_mograph_rebuilding_01.hip
  5. Music Visualisation

    More info here: http://simonfarussell.com/The-Creatures-of-Prometheus
  6. Hello I am trying to do something really simple and I am finding it to be quite hard. I am trying to rotate a box so that it carries momentum and settles down naturally as if it had mass. I have included a .hip file where I have attempted to do this manually but it is not the best. I am struggling to get the animation editor to behave and I have to keep closing and reopening Houdini as the Animation editor and the viewport are not marrying together. If anyone knows why this is or if there is a better way of doing this, (I have tried motion fx (spring)/chops but it failed miserably) I would be very appreciative. I have come a long way in this wonderful program but for some reason the animation editor feels really clunky in comparison with the rest of the program and I don't know if it's something I am doing wrong. Thanks dampened animation.hip
  7. MIDI Automation Channels

    Does anyone know if there's a way to bring in automation channels from MIDI (eg. volume, pan, fx controls) from MIDI files (not realtime)? I thought it maybe the Control tab in MIDI In but I've had no luck. Thanks, Simon
  8. I have a simple audio react animation that is conneceted to a CHOP network, just a few polygons with a simple extrude based on an audio trigger. However I want the objects to extrude sequentially; on the first audio trigger primitive 0 will extrude, then on the second prim 1 will extrude, so on and so forth, but have it be sequential and based on the audio trigger from chops. I attached a simple hip file, any help would be greatly appreciated Chops_sequential_ODFORCE.hip
  9. 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!
  10. Chops increasing value

    Hey, I was hoping someone could help me out with a CHOPS set up I'm stuck on. I'm looking for a channel to continuesly increase over time at a set rate, but with added intervales? That may no make sense so I have set up a scene to decirbe it. The image below show the white line which is what I'm after. Its a mix of the red (contast increasing value) with the sine wave pink line, but only the positve values, which then get added to the red line. Sorry if that's confussing, CHOPS is confussing! Any help would be really apprciated! Chops_Increase_01.hip
  11. Hi everyone, I'm trying to figure out a way I can offset a keyframe by a channel value. For example, I want to animate the uniform scale on a sphere but I want to be able to control the start frame of the animation by a channel value. I'm sure there is a way you could do this in CHOPS, but I'm not very comfortable using CHOPS, and thought there must be a simpler way of doing this! Thanks in advance
  12. Hi all, I've been trying to figure out how to create a linear ripple effect (i.e. rather than have a single point as the source, I'd like to source it from a line/selected edge/group of points, so that it travels across a surface like a wave.) Now, of course, at a basic level the 'waveform' SOP node performs this exact operation - *However* it can only generate a single wave at a time, and it lacks the signature 'decay' of the ripple over time. I had the idea of using the wave operation in CHOPS using a sine wave with decay on it, however any changes to the amplitude are applied across the whole waveform, rather than 'at birth'. So it doesn't create a dying wave, it just scales down the whole waveform. (see image). Any ideas on how to achieve this? (just as an FYI, eventually I'd like to control the decay length with an animatable paramater & creation/scale of the ripple from CHOPS with a trigger.) It seems like it should be super easy - Maybe I'm just having a bit of a mental block! :/ Any mind jogging greatly appreciated!
  13. Hi ladies and gentlemen, boys and girls, I have a job to create a kaleidoscope animation. I'm just learning how a Kaleidoscope works in real life and time is limited. Has anyone ever worked on such a project and can give tips on how to get started and maybe some math behind how it works? I've attached a video I found that has this effect created by buck (starting at about 16 seconds in). Any help here would be much appreciated really. Thanks in advance. Sherwin Williams - Kaleidoscope-SD.mp4
  14. I am trying to make some hda's to help speed up and distribute my mocap cleaning process, however when I make an HDA in CHOPS I get an error saying the sub-network has no output, and when I go to edit operator type properties, sure enough the outputs are greyed out. Anyone have an idea on how to fix this?
  15. Hi... I'm looking to attempt some image manipulation using CHOP nodes. Having used the Image CHOP to access the individual pixel data I'm lost on the best way to Export it back to COP context. I'm guessing I could do it with the VopCop2Gen COP, but thought their might be a better (easier) way? Cheers!
  16. Hello everyone, I wanted to transfer my animation from DOPs to SOP level, but I need to have a baked Curve. I managed to make a transfer between CHOPS > SOP using dynamics and export in CHOPS, but when I click Edit Data Channels and then Fit Panel > Copy to Export Destination (9 channels), I got a message "Status: 0 channels copied." The connection between CHOPS and SOP still works, I have a curve in Motionfx editor but I can't transfer it to Animation Editor and delete CHOP Network. Please Help.
  17. Keyframe Reduction?

    I am trying to work with Mocap data that I have recorded in Vicon Blade. I have an FBX of the solving setup that I have imported into Houdini and I have been able to work with it and get the setup where I want it to be, but I am running into an issue with file size. I am currently sitting at 189MB and I am pretty sure that about 95% of that is keyframe data. Unfortunately when I start working with the file it explodes in my memory and is becoming unwieldy. I am talking in the 25gb range. The Motion Capture data has placed a keyframe at every frame for all of the bones, which is definitely overkill. Is there any way of automatically reducing keyframes in Houdini? I have seen the tool in some other packages, but I am trying to figure out how to do it here. If there isn't a built in way to do it, is there any way I can delete keys in CHOPS, because I could see writing a VEX expression for doing it. Something along the lines of calculating the slopes and if the slope from one keyframe to the next is below a certain margin, delete. Or hell, I could just check concavity at each keyframe and only keep the ones where it changes, but I need to know if there is a way to delete the keyframes.
  18. Chops and changing topology

    Hi, I have a simulation and I want to filter points position after simulation is finished to remove jitter. But during simulation I am deleting geometry which is not visible (so that simulation runs quicker). So I cannot filter P attribute based on ptnum. Is there some option to run chops by id attribute like in Trail node Attribute to match? So that if point does not exist his value will be set to 0 or last available value instead of using attributes of another point. Thanks, Juraj
  19. Hey all, Anyone know how to reference video footage as a texture within Houdini? I know you can only input image sequences using CHOPs but even this stage is having me scratch my head. I have no experience in CHops so if anyone give me a few pointers of how to load in a sequence and then have this referenced as a 'diffuse' for a shader or whatever, it would be greatly appreciated. Cheers.
  20. Hi, Is it possible to get the channels of multiple objects in the chops context using one node? Perhaps importing bundles, or defining a list nodes? Thanks!
  21. Hello everyone, I would like to introduce my new Houdini training, "Houdini Rocket Ship". The idea behind this training was to create a project that will take the viewer through a variety of aspects of Houdini without making the project overly complex or technical. As long as you have a basic understanding of Houdini you should be able to follow the training Over the course of this project we will cover a whole range of topics which include Procedural modelling, Polygonal modelling, Environment Generation, Cloud modelling, CHOPs, RBD, Constraints Network, Smoke Simulation, Materials, Lighting using HDRI, setting up Takes, Rendering and Final composite in After Effects. There is currently a one week discount on the training series of $25. The offer will last till 17th October 2015. Trailer Final Animation for further information kindly click on the link given below http://www.rohandalvi.net/rocket
  22. First of all, I want to tell you what end result I want so you can solve my scene file or suggest other easier way of doing it. I want to get the transformations of these rbd dominos to object level. My first approach was to simulate rbd fractured objects then use dynamics chop to get that data and export it to object level but it got some problems. My second approach was to "get point data" from dops and do some matrix magic in VOPSOP with points and import that data through geometry CHOP so it can get exported to object level grid's transformation. I have tried to use orient attribute to my advantage but objects behave weirdly. Their positions are wrong. This is good exercise for you to use SOPs, DOPs and CHOPs interconnectively. You can see my file with both approaches, check out these nodes and tell me what am I doing wrong? I just want to apply the boxes domino data to grids in object level. Thanks! dynamics orient.hip
  23. Audio/MIDI

    I'm trying to bring in a midi channel but it doesnt show anything in the Motion FX view (Houdini 14). Is there anything I need to specify on the midinIn node? (If I open the midi file in something like quicktime I can hear something so the midi file should be fine). Also playing back audio is very jittery unless I set it to "Maintain realtime playback, possibly skipping frames". Is there a way to get smoother audio playback whilst playing back every frame? Even if I have nothing in my scene its still jittery...
  24. Hi guys, Sorry if this seems like a noob question but I just can't figure it out somehow. I need to apply some CHOPs function to ONLY the Z-axis. But I can't seem to only export the Z-axis in the channel node. I know its definately something simple which I might have overlooked. Anyone could help me with this issue Thanks! -Darren
  25. I am able to resample/ rearrange points along a curve shaped primitive by a ratio (0,0.1,..,1) attribute. using a look up chop for that. how do I do that same operation on a bunch of separate prims? loaded in chops I get a saw like curve representing all ratios from all prims in one curve, but what I like to have is one curve ranging from 0 to 1 in a linear fashion (representing just "one" ratio) so that I could change that shape with a spline chop. does this make sense? thanks in advance -sebastian edit: attached a hip resample_by_attribute.hip
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