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Found 40 results

1. ## Create Point That Lasts Only One Frame, At Random Time Intervals [SOLVED]

Hello Houdini vex wizards! I'm having a lot of difficulty trying to come up with a solution for this one myself. As the title mentions, I'd like a single point to be created for just one frame and then disappear again - I would also like this to happen at random time intervals as the frame number increases. For example the point will flash on for 1 frame, then maybe nothing for 10 frames, or nothing for 2 frames, then another point flash and so on. I'm not very good with time related things in vex, but would love to learn more about random time stuff if anyone has any ideas?
2. ## Random value hold 1 or -1

Trying to find a little trick to return random selection of two specific values (1 or -1) and hold it for a number of frames or i in a loop so it would be 1,1,1,-1,-1,-1,1,1,1,-1,-1,-1 or even better random ranges 1,1,1,-1,-1,-1,1,1,1,1,-1,-1,-1,-1,1,1,-1,-1 something like this but with better control of the distribution for(int i=0; i<10; i++) { float test = fit(floor(fit01(rand(i),-1,1)),-1,0,-1,1); int np = addpoint(0, pos); setpointattrib(0, "test", np, test, "set"); {
3. ## vellum grain random pscale

Hello, Someone could explain why in my basic setup, the grain have still the same size ? I try to have some random pscale. Thanks vellum-grain.hip
4. ## Random retiming of alembic instaces

Is there a way to retime alembic instances? i would like to have an attribute on my points (before the copy to points sop) that sets the speed of the alembic animation and the frame it starts. is possible to use an agent setup? that has this functionality built in as far as i have seen..although my alembic file is very simple geometry - not a rig or anything like that. Any tips?
5. ## random subdivision

I am interested in the files on this old thread and I want to have a look at the examples but I cant seem to open them on H17. Is it just me or are these files too old? any insight innto this technique? thanks! I hope Im not breaking any rules by lilnking an old thread.
6. ## Analogous Colors

I would like to color a set of primitives using random analogous color pairs. (or triadic/tetradic etc) The color sop node provides this information but only as a guide to choose from. How would i go about this? i suppose vex is the way to go but i don't have a clue as to which functions or what method should be used. Any tips?
7. ## Transformation to random value every few seconds

Hi there! I want to do a procedural animation where I randomly change the transformation every second or so. For example at frame 1 posX is 0, stands still and at frame 50 it moves to a random pos within 10 frames, pauses for 50 frames and moves to next random pos within 10 frames, pauses for 50 frames, moves to next random pos and so on. Unfortunately my knowledge of CHOPs is rather limited and I couldn't figure out how to do it with expressions based on @Time. Any ideas? Cheers, J.
8. ## How can I send random points into a group (over time)?

Hi guys; How can I select points in a geometry randomly over time, and send them into a group (until the end point)..? Thanks for helping. Random Points to Group.hip
9. ## Mixing different types of particle emission

Hi. I am currently working on an effect for tracer bullets on a fighter plane and I was wondering if there is any way to make the emission more controllable? Currently in my popnet I have 2 pop sources, one with probabilistic emission which creates a random emission pattern and one with it off so it emits particles at a constant speed. I have a switch setup so I can animate which emission method is used, but its either one or the other. I would like to be able to mix these 2 pop sources together so I could have a constant emission with added randomness created from the probabilistic source. ex: (20% of probabilistic, 80% constant or vice versa) Thanks hip file: machinegunfire_fx_ODforce_v012.hipnc
10. ## How can I create groups randomly?

I am trying to create some groups from a "guide groom" node so I can apply different kinds of hair generate later and give more variation to it. How can I get the guides randomly and create the groups from it?
11. ## randomly rotating boolean cutters copied to points

Hello Friends, Thank you for your time. I'm sure this is a very easy question, but for the life of me, I'm unable to get the result I want. I'm currently working on a dynamic stone wearing node. I'd like to be able to clip the outside corners with these little cutters. I've got most of what i want working, but I'm unable to get the cutters to have some variance in their alignment to the normals. So while I can have smaller or larger cuts, they always come out oriented to the normal, creating cuts that are equal on all sides. I want them to be more random. I should just be able to add slight randomization, but I can't get an attribute randomize to work, and have also tried an attribute wrangle that spins them around the main object's normals - which is cool, but given there is no detail on the cutter objects currently it doesn't serve any purpose. Does anyone know what I can do to add wobbling variance to the normals that control alignment of these pieces? Thanks again.
12. ## Looking for slight random variation in scale, pos, rot

Hello and thank you for your time. This is my first post here. Not only am i new to the site, but also Houdini - having only been poking around a month or so. So, here's my problem, I'm feeding an edge wear graph that I'm working on, an imported mesh. The mesh is for a modular wall kit. The mesh is broken up into watertight bricks. I run the edge wear on this mesh within a foreach connected loop. What I really want to do is achieve a more natural and worn old rock wall look. To do that, I'd like to introduce small amounts of randomness to scale, rotation, and position. However, since the bricks aren't copied to points, I'm struggling to get anything to work. In fact, I can't get it to work within the loop or pulled out on it's own. Hopefully the issue makes sense. This has to be a trivial thing, but all the tutorials i'm finding are for using point attributes and vops... and when I do that, I'm unable to group the points within each connected mesh. In general, i want these to stay rectangular. Thanks again for your help.
13. ## random pick point with vex

I just recently learn to use AttRandom to randomly pick point on a scattered field, how to I do it vex? random pick point.hipnc
14. ## TOPs Wedge Node : How to do distributed random?

Hi! I am trying to use the wedge node "random sample" option in a TOP network, but I want the random to have a probability distribution so that the randomness is not evenly spread. There is no attribute random node in TOP networks, so I am not sure how I could fetch some values generated elsewhere? Any idea how to achieve that?
15. ## Copy from a random Seed

Hello, i have an issue with the copy stamp, I created a Point wrangle where I choose randomly pieces from black or red color in a loop (its a building), so i created a variable with a random in my copy stamp and i want to paste it in a seed I created in the point wrangle, in order to copy different seed of my object on point, it doesn't work at all, it's always the same copy of the same seed... Thank for any advice, cheers
16. ## Random Sequence jpg to each grid

i have this geo and i want to apply random textures from a folder hierarchy. i friend of mine helped with some python code, so now i can select a folder randomly and then get the first image of the sequence with a little tweaking i managed to plug it in a quickshade and converting the file numbers to \$F4 or \$F3. so it should read the sequence BUT!! although i have the iterations attribute of the foreach meta node as a seed for the python script, the same image applies to all primitives. What is missing? Side question: why are the uvs rotating? any tip much appreciated, houdini forums are bit dry right now random_sequences.hip untitled.bgeo
17. ## Choose Randomly with even distribution

I have this expression to choose from a set of numbers randomly. (1,2,3,4,5,6....49,50) floor(rand(\$PT*ch("seed"))*detail("../node/","total",0)) My problem is that out of 50 numbers that i have only 23 make it after the expression. How can i make sure every number gets picked?
18. ## controlling random colors per bunch.

Hi, I'm running into a little issue where I'm trying to randomize colors over bunches of lines. Basically what I'm doing is making a small bunch of lines, say 6 close to each other. Then I copy that bunch over a distance around 500 times. (See attached file) After I divide all the lines into 3 groups with group by expression and I assign a different color to each group. However this splits up All the lines created, what I want is to randomize by initial bunch so each bundle of 6 lines has a mix of the three colors. What happens now that I want to avoid is the possibility of 1 "Bunch" being 99% one color which can happen working with this many lines. Doing the group split before copying and transforming will give me the exact same randomization thus giving you a repeating pattern. How would I best go about this? Randomized bunching issue.hip
19. ## Billard Ball Emit with Random Mat

Hello everyone I am creating a ball emitter (billiard ball). I would like to be able to create a ball of all colors with an instance that changes at random, to determine between several material. Do you have a little idea? I have link ma scene with the emitter A big thank-you Bille_sac_v03.hip
20. ## Randomly choose between 4 options

What's the most efficient way in vex to choose between 4 different options? Right now I am simply using rand and a series of if statements to check the resulting value. Is there a better way?
21. ## Vector manipulation in VOPS

Hi guys, I'm building a volcano with chunks of debris flying out the top. I figure I'll just copy rock geo onto points emitted from a popnet. My understanding of vector math/manipulation and control is pretty atrocious; being a visual learner, I'm trying to focus on vops for now, even if the same thing could be accomplished in one line in a wrangle. I was wondering what the best way would be to assign random vectors to points. This is how I've attempted it: https://imgur.com/a/XAQ9ZCk However, when run through the popnet, they all seem to bias to the right, displaying a lack of randomness. From looking at the vopnet, is there any reason why this would be? Without adding a noise, would you guys have suggestions for a better method? I'm not against using a noise, I'm just trying to understand what's going on, and why my current set up is failing to randomise effectively. Also, does my fit range seem appropriate? It looks weird to me, but the defaults were no good. I've attached my hip just in case any of that is unclear. Hope you can help me out; Being an absolute ditz, Houdini math breaks my brain... vector_control.hipnc
22. ## Boolean random seed per stamp??

Hello, I'm trying to create some really basic glass debris (small on screen and limited in poly counts (games)), so instead of using material based debris (too directional) or voronoi fracture (too hexagonal looking), I thought I would use Steven Knipping technique and use booleans. -create one glass panel -add points -attribrandomize the points -copy to points grids for cutting -boolean scatter the glass panel with the cutting grids -copy stamp the panels ...wishing to use stamp to add randomness to attribrandomize. It works great except that I can't get the randomness of my stamp attribute to randomize the seed, so all panel look the same. I'm creating a rnd attribute in the copy stamp SOP with the following expression: rand(\$NCY) and in the attribrandomize under options tab>Global seed I enter: stamp("../copy6/", "rnd", 0)*12345 If anyone as a minute to take a look or has any suggestion that'll be fantastic!! thanks BooleanStamp.hip
23. ## Random Scale of Spheres

Hi, I'm trying to randomize the uniform scale of some spheres which are being copied to points. However, nothing I've tried is working. The best result is using a transform node, but all the spheres merely scale to the first parameter and ignore any type of randomization. The attached file currently has an app wrangle using some vex to randomize pscale that was defined in an att created node, but it's throwing errors I don't understand how to fix. Thanks in advance... wk5_terrain-02.hipnc
24. ## Object instance - randomize instance parameters

Hello, I am having trouble randomizing parameters from instanced geometry from within an "instance" subnet. Say for example I wanted to randomize the speed of an instance's animation (on the sop "timeWarp" node), or the start frame of the instance's animation (on the sop "timeShift" node), or perhaps randomize it's material. Please check attached file. Thanks in advanced. instance_randomize.hiplc
25. ## trying to roate pieces of my burger randomly

hi all i'm trying to add a way to rotate each of my pieces of my burger randomly - but i cannot suss it for love nor money can anyone help please? @mestela - i found a simple wrangle from you to shift all the pieces upwards (burger exported from maya!) ... now i just want to add a little rotation but i cant figure this out tried primitive wrangles and pasting expressions into transform nodes - no idea
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