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Showing results for tags 'Expression'.
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Hi, OK my scene is roughly a PDG setup with some work items, those have all been merged together into a single work item where all the attributes are merged into arrays. I am looking to access those attributes using component syntax ( @pdgoutput.1 or @pdgoutput.2 ). This works when I manually type in the component pull. I cannot get this to work in a For Number loop using the iter count. How can I build an expression that uses the string of the first part of the attribute ( "@pdgoutput." ) and concatenates it together with an detail interger in a SOP loop like @iteration? I have tried such expressions @pdgoutput.`detail("/obj/geo/merge1","iteration",0)` or even strcat("@pdgoutput.",`detail("/obj/geo/merge1","iteration",0)`) Though these all resolve to 0 I have thought to also try something like atof() though that wasn't working for me either. Does anyone know how to work up pdg array attributes in an expression like this? Is there a better way to do this?
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I want to know if a group exists in my geo stream. Found a solution in this old topic but doesnt seem to work Any ideas? check_for_group.hip
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Did I do something wrong here? Getting a "Read only expression on left side of assignment" error... could someone help me solve it.
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Hi guys, I was watching John Moncriefs rock generator talk and I cannot work out the expressions used in the mountain offset to generate random iterations (around 11 mins). There are some really helpful breakdowns in the comments however I cannot get it to work. I've attached a scene file, any help would be greatly appreciated Thanks in advance. Random_Rocks.hip
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Hello! I am trying to implement python expressin in Object Merge node in parm "objectpath1" to get geometry from connected nodes to parent geo. So as final result if you connect/disconnect first input of test node geometry should switch to another one. Actually script working fine and storke of parm updating if i connect or disconect ANIM node, but object merge node do not updating geometry while i turn on/off "Enable Merge" toggle on object merge node. It's seems node just not cooking properly. Any suggestions how to solve this problem? Or maybe hscrip variant? P.S. check test setup in hip uploaded switch.hipnc
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Hi all I am currently working on a feasibility test in order to build up some understanding of procedural modelling, I have a question regarding expressions in Houdini today, I have received great help from artists in the community which I am very grateful for, thus has helped me get this far, the new question I have is, I would like to delete all the lampposts based on the location of a building box I am using to represent a futuristic house, this box will be a model of a house and will have details like windows and doors later on, with this in mind, am I better of using a proxy box over my model which deletes the lamppost inside the box's radius or is this possible with the actual asset itself?, I have attached an image of what I mean including the current expression within the delete node thank you . Kind Regards Ahmet.B
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Hi guys, I am trying to automate my alembic imports by using a string replace on my File path. For example: on my alembic File Name parameter I've written the expression - `strreplace($HIP, "home/fx", "fx/waterfountain_v001")`.abc I would like to be able to replace the version number with a wildcard so that it picks up the file regardless of what the version number is, but an (*)asterisk doesn't work. How should that be scripted? Thank you in advance!
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Hey Guys, i got a question. I got a vellum sim and i am emitting every 8th Frame one sphere into my sim. I did it with -> $FF % 8 == 1 but now i want that emission just between Frame 1 - Frame 48. So between F1 and F48 i want every 8th Frame an emission. How can i get this with an expression? Cheers and Thanks!
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Hey all, I've been trying to learn more about how loops work, right now I've got a faerie, its wings are expression driven (Sin function tied to a controller) and I have the main build in one shelf with a point cloud that it's instanced to in another. I needed to figure out how to randomly reverse the sin function for points/particles so that they aren't all flapping in unison. Right now I'm close to starting over because I learned maybe a for-each point loop with a timeshift could help, but I feel as though there's a simpler way. Granted this is my third project total in houdini so I'm VERY inexperienced with this. I have the Tokeru site up to help kinda learn how loops work but I'd love some guidance on how to get this to work. Also, what am i screwing up? I tried to export the animation so I could just re-import the baked animation to a particle source so as they spawn in they're offset from each other just based on life, but it doesn't save the animation. Do expression driven animations get baked to disk? To clarify my focuses: I need to completely offset the flapping wings of the instanced copies so they aren't in unison PS: Thank you to anyone who helps, I appreciate it. test_Navi.hip -
get orient attribute from point normals
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To create a round fencing around house, every cube is aligned in same direction, how can we make to face towards the inner circle like real fence...???? -
Hi, I am studying python to set a parameter of string (cachePath) by script. After executing the code, ideally it pastes original, "`chs("resouceA")`_`chs("resouceB")`", instead of expanded result "G:/Projects/RnD_000_001/geo_element " So far, I am thinking two methods: A a = r(\"\`chs(\"resouceA\")\`_\`chs(\"resouceB\")\` ") # this way is too many back splash and so confusing B resA = hou.node('.').parm('resourceA').unexpandedString() resA = hou.node('.').parm('resourceB').unexpandedString() a = resA + resB # this way is ok, but when there are 5-10 parmeters, it would be too much work. Do we have a simplest way or special command?? Ideally something like this: a = unexpandedExpression("`chs("resouceA")`_`chs("resouceB")` ") Thanks
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Hi everybody, I have one question I'm creating procedural stairs so I have created an attribute name(Steps) and another is (NumPillar), so what I want is, in edit Parameter Interface we can set range but I want the max range should be same as steps value as you can see in image. Blue color indicates steps and red indicates pillar in image file Pillars.jpeg
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Hello, i trying to do something simple but i am knid of new to houdini so i dont know the tricks yet. i have a float number in a for loop that i want to divide by two every iteration. What is the appropriate expression for that?
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Hi just wondering if any one could give me any advice on how to write an expression which would set the gravity to 1 for the first 30 frames, back to 0 for until 180 where i would turn back on. At the moment i have if($FF >= 30,0,1) which sets the first 30 frames to active but I'm struggling with re-activating it at frame 180. Any help would be appreciated.
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Hey, I got a very Basic questin regarding an Expression. So this one: point(stamps("../applyrel1", "SOPPATH", ""), ch("ptgroup"), "P", 1) I´m kinda wondering where "ch("ptgroup") Points to. Ist aiming to a Group Expression Node which contains two Points. But I cant see any actual channel Name called "ptgroup". Is it something inherent or hidden? Ist working but I would like to know why.
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Hi, I've tried to cache out .obj files which have the same naming as their import counterparts. I managed to write their original name into a string detail attribute (for example "one200_300-236-58_korpus.obj") - next I thought I could reference those attributes in a filecache node ($HIP/`detail("filecache1",attribute1,0)`) but nothing happens - I just get a file called 0 without any .obj Does someone know whats wrong with my setup? Thank you
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I want to get number rounding to the second decimal place. like this -1.2345 -> -1.23 i was do that in Houdini 16.0 : But I cant do that in Houdini 16.5 how can I? sorry, I did not write that I used it Font node. i'd like to use this on Font node. roundDec_example.hipnc
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Hi, I constraint two objects together with chops. Everything works until I use expressions in my parent object. What do I have to do to fetch expression values into chops? kind regards Jon express_chop.hip
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hi I was trying to use Sopsolver expression to output the previous timestep, but i am not getting the result. this is the expression i use inside sopnetwork using object merge node. stamps("../OUT", "DATAPATH", "../../.:agents/Geometry") flocking_system.hipnc
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I've been working on trying to simplify how I can make tear drop shapes (bombs, fuselages, etc). So I got most of it figured, until I stumbled on losing a point during the copy sop. Im always missing the last point from my ramp. Any help would be appreciated. I find myself fighting my brain over "value" and "pos" till the cows come home. HAA. TIA Bill odforceExport.hipnc
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Hi guys, As i have pre-roll in my simulation, i am starting my sim from 1000th frame. but this is creating a problem, when i am using the "$F" , because i know it is recognising as frame 1. so that is the help i am looking forward here. how do i fix that ?? i want this $F to be the 1000th frame not the usual first frame. if suppose, there is no solution for that , then all i want is... """i have 100 rigid pieces, and i want each frame to have different pieces staring from 1000.""". i type in piece$F in the blast node, and its starting from frame 1.
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I'm trying to drive a BlendShapes' SOP blend parameter using a point attribute, @fade. The @fade is a point attribute and have it's value animated. But the blend parameter doesn't appear to read this animated values and keep showing 0 instead. The question: the blend parameter doesn't work with point attributes? I tried VEX and Hscript forms (@fade and $FADE). The second crashes.
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Hey, I got a really stupid question but I can't get it to work ATM. I want to put an expression in e.g. a fluid source node in dops. Something like "if($FF)<225, 1, 0)". So when smaller than frame 225 take 1, else 0 (or another expression like a sin curve). What am I missing here?
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I'm using Houdini to render point clouds from depth images, and have everything working for a single frame, but can't get it to evaluate each frame in a sequence. I'm using an expression in the parameter that reads in my image files, so the file path looks like this: D:/UNREAL_WORKING/Brush_VR/Video_Captures/Character_Front/Point_Cloud_Map_01SceneDepthWorldUnits.$F4.exr The $F4 is correctly becoming '0001' on the first frame, but when I slide the timeline around, nothing changes. When I click Expression->Expand String Value, I can see that at each frame it is producing a string that should be reading in the correct file - if I write that same string manually, it pulls in the right file - but it's not actually evaluating the data from the image. What do I need to do to make sure the network is cooked each frame?
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