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Found 30 results

  1. So, i tried something from scratch for the first time, albeit very simple... almost there! That being said i did got stuck up... 1. SOFT SELECTION GROUP: i am trying to apply some animation to a bunch of lines through a pointvop. i want the animation to be limited to all the points but the ones at the ends of the lines, i create a group of those points... it works,- but could be better if i could make the animation blend to the static points at the end. 2. FADING TRAILS: At the end i added a bunch of trails with some lag and or jiggle. i am coloring them with the width attribute through an 'attribute create' node. Is there a way to make each trails less opaque than the previous. (if this can't do the job, any other tips?) 3. NOOB VOP NETWORK CRITIQUE: I am pretty sure my vop network is far from efficient, i would appreciate if anyone has some tips to make it more logical/ efficient. I hope i was able to explain myself. (i have attached a screenshot for reference) d.
  2. By default, when selecting components or make groups, houdini shows those selections as "light cyan" color... but the background of the viewport is almost the same color.. bright cyan. Sometimes dificult to distinguish. I want to change the default selection color to another one(green or orange), but not stablishing them in Group and attributes window. ¿¿Where is the menu or option in preferences to change this parameter?? Thanks in advance.
  3. Is there a way to define a group of primitives based off the faces created by PolyCap?
  4. Hi, a concrete slab ( box with size 3, 0.2, 1.5) after a voronoi fracture, I'm with prim groups: piece0 piece1 piece2 ... I'd like to select a few of them (pieces at the border of the slab) I know how to do it manually in the viewport / component groups / enable group selection or press 9 but how can I use this in a procedural way ? Like in a group node, with a bounding box ? It will only group the primitives, is there a way to extend the selection to connected geo ? must be possible..
  5. Hi guys, here are the files I used for the last Vancouver Houdini User Group in case anyone wants to take a look. My presentation was about writing the Group SOP in VEX and trying to optimize it. I wrote everything in a wrangle, and it works great as a preset in a point/prim wrangle. I also made a Digital Asset, although it's not a VEX operator because I couldn't figure out how to make it work purely in VEX because I need to use the group bindings from the Wrangle and I'm not sure how to implement that in VEX. Anyways, the OTL is just the wrangle with the parameters promoted. In the presentation file you can take a look at the speed tests of the Group VEX vs the Group SOP. The difference in performance is pretty similar if you have a few points/prims, but once you go above 1 million the performance difference really starts to kick in. The Group VEX becomes exponentially faster than the Group SOP the more points you have. The difference can really be seen when you group by object and when you group by volume. I also made those 2 modes work with primitives. Here are the files in case anyone wants to take a look at the code. Feedback is greatly appreciated! group_vex_jeronimo_maggi.hipnc vhug_presentation_jeronimo_maggi.hipnc group_vex_jm.hdanc custom_group_sop.vfl
  6. I have primitive groups set up in SOP level, something simple like a box with a voronoi fracture applied with the inside and outside primitive groups. How can I access this primitive group in shop context? I am trying to compare whether or not a shading point belongs to a specified group so I can create a mask. I can create a attribute at sop level to store the group information on the points and that works, but I want to do this in the shop context because the geometry will be heavily subdivided and displaced and I need the accuracy. Any thoughts?
  7. Hi guys, a friend was asking if he had some moving points and for example there's a group by bounding box, so some points enter the group for a few frames. Is there a way to delete those points from the entire sequence? I was wondering the same thing myself, so I gave it a go using a SOP Solver. Check out the example file. delete_red.hipnc
  8. Hey guys, Hopefully this is a quick one. I was wondering how I could find the average position of a group of particles (and store the position as an attribute on the particles in that group)? Say I have two groups, A and B, and I want to find the average position of the particles in group A and create a force on the particles in group B to go towards that point (center of A), and at the same time have all the particles in group A move towards center of B. POP Group A -> Center of POP Group B POP Group B -> Center of POP Group A Thanks
  9. Hi all, Consider you have a line made from 2 points. You subdivide the line to give you a new point in the middle, how can you add this new point to its own group? As a bonus, how could you group the resulting geo of any SOP?
  10. Hello, I'm looking for the best way to prevent an attribute from changing once it has reached a certain value. I'll have other benefits from this, but for now it's to control the "active" state of some points via an animated object. I'm setting a group of point with a bounding sphere grouping, then I wrangle i@active = 1 for that group. but, obviously, when a point is back out of the sphere, it's out of the group and gets a @active = 0 again. I'm wondering if it's doable in VEX (if active becomes 1 then never change again) or if there's other tricks to do that. here is a simple hip file where I move the points up when they are in group1, so for this exemple, I would like the point to never come back down if they get moved. Thank you! I've seen a way to do that in a particle tutorial, where the colours get changed and is then prevent from changing back when outside a box, but I just can't remember, and can't get my hand on that video again : / OD-F_keepattrib.hipnc
  11. Hi, I'm struggling :/ I got a tall box (a building) I'm voronoi fracturing it. I got on big chunk at the top and many smaller at the bottom. I got a glue constraint network with some link deleted, so they can fall on the ground. Now I'd like the big chunk to be breakable so it can fracture when hitting the ground. So I use make breakable shelf tool and I would like to apply it to the big chunk only. There is a group field at the yop of the "voronoi fracture configure object", but I just can't manage to select the big chunk only. I should mention that I'm importing the fractured box as packed rbd. If I don't I have access to pieces in that group field, but with packed option, no more. There's a s@name attribut, but I can manage to use it :/ I'll make a hip file soon, but in the mean time, if someone knows where is my mistake or a solution...
  12. Hi, I have a problem which I don't know how to solve. In short I have a geometry objects which are grouped in few different groups. My objective is to use PRIMITIVE SOP after grouping the primitives, but I would like the groups to act as though each of them is a primitive. In the attached example, the pink group is group_01, the rest is group_02 and if I apply PRIMITIVE SOP to it and do some translations, I would like to move the grouped primitives together. Any ideas on how to solve this problem? Like this
  13. Ok, I have many objects separated into point groups by unique suffixes. I'd like to split the suffix integer value from the array of group names. Then assign that integer to a custom attribute. I'm terrible at VEX so any suggestions would be greatly appreciated.
  14. hey, i have a geometry that i am fracturing with voronoi. i need to separate these pieces into active and passive pieces. instead of selecting them by name, i would like to select all the pieces within a bounding box/sphere. i thought about using a group sop and selecting by bbox, but this selects points or primitives, and not my piece* groups from voronoi. any ideas? thank you so much!
  15. Hello guys!! I just discovered today that I do not have certain nodes in houdini that houdini has had since houdini 11. I have tutorial files from cmivfx and I looked at the created time for the node and it was 2011, whatever version of houdini that was. I'm using houdini 14 and it doesn't have the nodes: add point to group create point group point in group I am installing daily builds! What is going on?? Someone please help. Thanks!
  16. I am trying to create a primitive group with using a syntax something like this; n = hou.node('/obj/geo1/grid1') g = n.geometry() p = g.createPrimGroup("myGroup") I get an error when I do the last line. What is the way to create primitive or point groups with python, if I just want that group to have all the prims/points in that geometry? Thank you for the help, Alican Görgeç
  17. Hey everyone, I am about to move to Montreal for work and I was wondering if there's a Montreal Houdini User Group up in Montreal. If so, it'd be awesome to meet up and share ideas and knowledge and whatnot
  18. hey guys how can I specify a sop group instead just a sop, inside a Sop Path from a RBD Object node? Thanks
  19. Hello, I coming from Cinema 4D and I wanted to model something simple in Houdini. Here what I want and where I've stuck: I have done it in houdini with group selection: but after that I want to create a group of points and then make extrusion and sweep. something like this: My idea was, to create a group of points (what I did) and then extrude them with PolyExtrude with group selected, but it doesnot work. Then I've tried to create something like Sweep where I have profile and spline (what I actually did in Cinema 4D), but I don't know how to do it and I'm not sure about is it good way to do it or not. Since I have Point-Group, whenever I use PolyExtrude or PolyBevel, it's doesn't do what I want. My idea is take this point group and connect them together and create something like Spline and then use this spline as a path for extrusion. Please explain me how can I do it, I've watched many tutorials, but when I started to do something mine, I've stuck on fifth node I still digging inside, but as a newbie I have no confidence in my steps. Please thank you
  20. Hi, everyone! I get some polygon group such as S1 S2 S3 S4…… How can i delete the group random such as S1 S5 S8…… and S1-S10 in delete node by expression. I can random seletion group by foreach node then delete it. But i can not figure out a simple expression in delete node. I have search for tips form forums, it may somebody already post a same problem, but i failed. Any help. Thanks so much! random_delete_group.hip
  21. With some Python scripts, I can get list of objects in a group. I guess there is an expression way. But I can't find it. If you know this, please tell me. Thank you.
  22. Hey guys, I'm looking into a way to group primitives based on their UV tile. I know how to do this in the viewport by switching to the UV view and selecting the faces of the geometry in the tile I want and clicking group in the shelf. However, I'm looking for a way to do this in vops or using an expression. I want a procedural way to do this. I don't know if the tiles are numbered or how I would go about doing this.
  23. Hello, I am still new to Houdini and got the following Problem to solve: I got a fractured Object and want to use a Box to Group a specific area of the fractured Object. BUT I want to select only whole Pieces. In other words: If one or more Primitives with the Attribute NAME are in Box, assign ALL Primitives with same Value of Attribute NAME to Group "X". Example 1: If Prim A (with Atb. NAME = "Piece5") is in Box, assign ALL Prim with Atb. NAME == "Piece5" to Group "X". Example 2: If Prim B (With Atb. NAME = "Piece2") and Prim C (Atb. NAME = "Piece9") are in Box, assign ALL Prim with Atb. NAME == "Piece2" OR NAME == "Piece9" to Group "X". So in the end it should work for n Primitives in Box. How can I achieve this? Thanks in advance Lukas
  24. Small tools for group points or primitives with unshared edge rule group_shared_unshared.otl
  25. With the delete/copy node combination, I want to loop over each group of the input separately and combine the results at the end. This is the input node: As you see, it has two primitive groups. In the delete node where this node flows into, I'd like to delete all groups except for the "current one". Basically, I'm looking for the HScript string expression that returns a group name by index. Something like this: primgrouplist("../all_junctions")[0] Off course this doesn't work, because that just returns the first letter of the string returned by primgrouplist. How do I return thenth group in primgrouplist? Thanks, Waldo