Is there any solution to find the intersection points of a parametric curve (bezier ot nurbs) and a circle in VEX (geo wrangle node) ?
I understand that you can solve this through a curvesect node or by own realization a Newton-Raphson function or something similar, but maybe there is some faster way?
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Technical Discussion » Intersection of a bezier curve and a circle in VEX ?
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- Dronson
- 41 posts
- Offline
Technical Discussion » Karma - Animated Texture with VEX shaders
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- Nitzan Tregerman
- 7 posts
- Offline
Hey everyone,
I'm working with the karma ROP node and VEX shaders.
I have a problem with importing an animated texture with $F3 expression
Karma is only able to read the first frame of the texture.
My workflow is fully in the MAT context and I don't work to get into LOPS / Solaris
is there a workflow that allows karma to read animated textures from the MAT context?
I'm working with the karma ROP node and VEX shaders.
I have a problem with importing an animated texture with $F3 expression
Karma is only able to read the first frame of the texture.
My workflow is fully in the MAT context and I don't work to get into LOPS / Solaris
is there a workflow that allows karma to read animated textures from the MAT context?
Technical Discussion » How to set display flag in scene view ?
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- chrisc
- 5 posts
- Offline
Hi,
In the Scene View, you can select nodes with PageUp and PageDown. Is there a way to set the Display Flag in the same way in the Scene View ?
Thanks for your time, Chris
In the Scene View, you can select nodes with PageUp and PageDown. Is there a way to set the Display Flag in the same way in the Scene View ?
Thanks for your time, Chris
Houdini Indie and Apprentice » Layout of UVs by models that are close in distance.
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- tealike
- 1 posts
- Online
Hello
I want to layout uvs by models that are close in distance.
I layout the UVs for each group and tried to achieve my goal by using the "Connectivity" feature of the "UV Layout Sop".
However, this method causes the following two problems.
1. Padding spacing is not uniform.
2. There are many useless UV areas.
any idea?
thanks in advance.
I want to layout uvs by models that are close in distance.
I layout the UVs for each group and tried to achieve my goal by using the "Connectivity" feature of the "UV Layout Sop".
However, this method causes the following two problems.
1. Padding spacing is not uniform.
2. There are many useless UV areas.
any idea?
thanks in advance.
Technical Discussion » Problem using 'Points From Volume' Node - Not enough points
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- Fletch04
- 1 posts
- Offline
I'm new to using Houdini and I'm using it to create a torch flame for a school project via a tutorial on youtube. The guy in the video imports the torch geo, duplicates it into a separate geometry folder (for the pyro sim), via an object merge and then blasts the handle away so its just the tip of the torch that's going to be affected. He then poly extrudes the mesh so it has some depth and then attaches a 'points from volume' node.
My issue is that in the tutorial the creator uses a point separation value of 0.003 to get a decent saturation of points, but when I use the same value or even a lower value such as 0.001, I get nowhere near the same amount of points as he does. Another problem is that adjusting the value lower than 0.001 basically freezes my pc so that isn't an option, and I shouldn't need to considering his adjustment of the point separation parameter is basically instantaneous whereas mine takes up to 10 seconds at worst to make the change. I have tried placing a transform node after the object merge and messing around with the value to see if that would give me more points but had no success. I have tried this on two separate machines and tried it with two versions of Houdini on each and have gotten the same result all 4 times.
I'll attach the tutorial video if someone would like to try recreating my problem. I'll also include both a screenshot of the points from his tutorial with the 0.003 value as my own project with the same value.
*Its worth noting that I'm using my own torch model for this project instead of his, but my geometry has a similar amount of subdivisions and spacing so it shouldn't really be an issue in theory.
Tutorial: https://www.youtube.com/watch?v=qX3BGxzKnBA [www.youtube.com]
My issue is that in the tutorial the creator uses a point separation value of 0.003 to get a decent saturation of points, but when I use the same value or even a lower value such as 0.001, I get nowhere near the same amount of points as he does. Another problem is that adjusting the value lower than 0.001 basically freezes my pc so that isn't an option, and I shouldn't need to considering his adjustment of the point separation parameter is basically instantaneous whereas mine takes up to 10 seconds at worst to make the change. I have tried placing a transform node after the object merge and messing around with the value to see if that would give me more points but had no success. I have tried this on two separate machines and tried it with two versions of Houdini on each and have gotten the same result all 4 times.
I'll attach the tutorial video if someone would like to try recreating my problem. I'll also include both a screenshot of the points from his tutorial with the 0.003 value as my own project with the same value.
*Its worth noting that I'm using my own torch model for this project instead of his, but my geometry has a similar amount of subdivisions and spacing so it shouldn't really be an issue in theory.
Tutorial: https://www.youtube.com/watch?v=qX3BGxzKnBA [www.youtube.com]
Houdini Lounge » baking out color from the heightfield visualize node?
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- circular_ruins
- 28 posts
- Online
hey, I'm working with a heightfield and I like how it looks with the heightfield visualization node, is there anyway to access this information in COps, to use as a starting point in texturing?
Technical Discussion » translate arnold materials to MaterialX
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- luoqiulin
- 297 posts
- Offline
HI,i want to translate Material Network Nodes or .mtlx to the real MaterialX file or real MaterialX network.
sure there is an optin to export materials as .mtlx. but i need replace the origial arnold shaders to standard mterialX shaders. then i can use karma to render the same asset.
here is a tool "KTMaterialXTools" did this in katana Your text to link here... [github.com]
so maybe anywhere has houdini tools.
sure there is an optin to export materials as .mtlx. but i need replace the origial arnold shaders to standard mterialX shaders. then i can use karma to render the same asset.
here is a tool "KTMaterialXTools" did this in katana Your text to link here... [github.com]
so maybe anywhere has houdini tools.
Technical Discussion » COP output to indexed colors
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- merlush
- 1 posts
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Hello! The my main task is to make a mask for a terrain that will contain indexed colors 0-255. Each index is a material in a game engine shader. My pipeline is eroding and modifying a terrain, exporting raw bioms masks to COP, set a particular RGB 0-255 color, quantize and mix them and finally export to Photoshop with converting to index colors with custom palette. Can I avoid the last step somehow and export indexes from Houdini?
Thank you.
Thank you.
Solaris » instance procedurally placed assets
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- evanrudefx
- 164 posts
- Offline
Hello,
I need help coming up with a way to instance assets in solaris. I made a HDA (at sop level for proof of concept) that builds simple characters by taking modular assets and placing them. We plan to have a lot of these characters in a scene at once. Since each character is grabbing parts from the same USD asset pool, it makes sense just to instance the assets.
The hda I made at sop-level was great for proof of concept, but I am guessing for this to work (as in be instanceable in solaris) I would have to remake the HDA at LOP level?
My guess would be to make a lop HDA that does this:
1. Import the modular USD assets.
2. Place the assets to build the character. The way I did this in sops was by using copy to points. I had points where each piece needs to connect. For example, to connect a head to the torso I made a point at the location where the head needs to connect to the torso. I used a copy to points to either randomly copy one of the head assets or allow the user to manually specify a head asset to copy to the point. It seems I can do the same thing at lop level using the instancer lop. Since inside the instancer lop is sop level, I could use sops (just like my old hda) to create the points at the right locations for the instancer lop to copy the modular assets to.
3. Final step would be to export this character that is made from the original USD modular assets pool to a USD file.
Now lets say we made 100 characters this way. Would there be a way to import those 100 usd files in a way where the modular assets are being instanced? Because each of those character USD files we created are all going to be referencing the same original modular USD assets. Is something like that even possible? I hope that made sense.
Thanks
I need help coming up with a way to instance assets in solaris. I made a HDA (at sop level for proof of concept) that builds simple characters by taking modular assets and placing them. We plan to have a lot of these characters in a scene at once. Since each character is grabbing parts from the same USD asset pool, it makes sense just to instance the assets.
The hda I made at sop-level was great for proof of concept, but I am guessing for this to work (as in be instanceable in solaris) I would have to remake the HDA at LOP level?
My guess would be to make a lop HDA that does this:
1. Import the modular USD assets.
2. Place the assets to build the character. The way I did this in sops was by using copy to points. I had points where each piece needs to connect. For example, to connect a head to the torso I made a point at the location where the head needs to connect to the torso. I used a copy to points to either randomly copy one of the head assets or allow the user to manually specify a head asset to copy to the point. It seems I can do the same thing at lop level using the instancer lop. Since inside the instancer lop is sop level, I could use sops (just like my old hda) to create the points at the right locations for the instancer lop to copy the modular assets to.
3. Final step would be to export this character that is made from the original USD modular assets pool to a USD file.
Now lets say we made 100 characters this way. Would there be a way to import those 100 usd files in a way where the modular assets are being instanced? Because each of those character USD files we created are all going to be referencing the same original modular USD assets. Is something like that even possible? I hope that made sense.
Thanks
Houdini Indie and Apprentice » Issues with caching my simulation
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- Adhu11
- 1 posts
- Offline
I have been learning houdini for some time and I am facing issues with my caching. Whenever I keep my sim for caching, my laptop starts to not respond or cook any frames after some time. I got better results when I cached my sim into my ssd. Still the problem continues after some frames.
Maybe I could buy a SSD and install it in my laptop but it supports only gen 3 nvme.
Will buying an external ssd work or should i go for upgrading my ssd to larger storage internaly.
Laptop specifications - intel i7, 2x8 gb 3200 MHz, 256 ssd, 1 tb hdd
Maybe I could buy a SSD and install it in my laptop but it supports only gen 3 nvme.
Will buying an external ssd work or should i go for upgrading my ssd to larger storage internaly.
Laptop specifications - intel i7, 2x8 gb 3200 MHz, 256 ssd, 1 tb hdd
Houdini Engine for Unreal » Exporting a Solaris network to Unreal Engine
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- KatanaPoland
- 9 posts
- Offline
Hi, I'm trying to export a solaris network from Houdini to Unreal, here's an example:

In Unreal I'd like to overwrite these .usds inside the red rectangle. Is this possible using Houdini Engine for Unreal or any other method?
1. I've tinkered with sending geo nodes from Houdini to Unreal, adding geometry then sending them back to Houdini using Houdini Engine for Unreal and Node Sync. I now know this plugin doesn't work with sending nodes from Solaris context as such (as explained here https://www.sidefx.com/docs/houdini/unreal/inputs.html).
2. I've also tried collapsing the Solaris network into subnet and then that into a .hda, with errors:

3. I've tried Unreal's USD Importer plugin.
Here's a different network I tried this with(ignore the error exclamation, was hacing issues overwriting files):

And here's how it gets imported when importing Main.usd:
-on the left: the scene structure loads correctly inside the USD Stage window in Unreal
-on the right: only Root and Sky are in the Outliner, no Cameras or Lights (because they're Scopes?)
In Unreal I'd like to overwrite these .usds inside the red rectangle. Is this possible using Houdini Engine for Unreal or any other method?
1. I've tinkered with sending geo nodes from Houdini to Unreal, adding geometry then sending them back to Houdini using Houdini Engine for Unreal and Node Sync. I now know this plugin doesn't work with sending nodes from Solaris context as such (as explained here https://www.sidefx.com/docs/houdini/unreal/inputs.html).
2. I've also tried collapsing the Solaris network into subnet and then that into a .hda, with errors:
3. I've tried Unreal's USD Importer plugin.
Here's a different network I tried this with(ignore the error exclamation, was hacing issues overwriting files):
And here's how it gets imported when importing Main.usd:
-on the left: the scene structure loads correctly inside the USD Stage window in Unreal
-on the right: only Root and Sky are in the Outliner, no Cameras or Lights (because they're Scopes?)
Edited by KatanaPoland - 2023年9月13日 06:14:04
Technical Discussion » SOPs vs DOPs
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- anbt
- 61 posts
- Offline
Hello,
I think this is quite an undocumented topic and thought it would be informative to know the limitations of each SOP solver vs its DOP big brother.
So I am calling everyone who would have a few minutes to spare to write down what are the limitations of each SOP systems and when DOP is required. This would be super useful.
Cheers!
I think this is quite an undocumented topic and thought it would be informative to know the limitations of each SOP solver vs its DOP big brother.
So I am calling everyone who would have a few minutes to spare to write down what are the limitations of each SOP systems and when DOP is required. This would be super useful.
Cheers!
Edited by anbt - 2023年9月13日 03:56:00
Technical Discussion » Global defaults for Digital Asset Save Preferences
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- j0nc
- 5 posts
- Offline
Hi,
I've been trying to set some studio wide defaults for the Digital Asset Save Preferences without much luck so far. Specifically i've tried using the same approach as discussed for other config files here [www.sidefx.com] for `vhda.config` which contains the required settings. I've tried appending `.nosave` as suggested, which works fine for `hopmanager.pref` for example, but `vhda.config` doesn't seem to be getting picked up either with or without that. I'm adding the config file to the `HOUDINI_PATH` alongside `hopmanager.pref` which is working correctly.
Is it possible to set global defaults for this dialog? I'm currently working on Houdini 19.5.682.
Thanks,
Jon
I've been trying to set some studio wide defaults for the Digital Asset Save Preferences without much luck so far. Specifically i've tried using the same approach as discussed for other config files here [www.sidefx.com] for `vhda.config` which contains the required settings. I've tried appending `.nosave` as suggested, which works fine for `hopmanager.pref` for example, but `vhda.config` doesn't seem to be getting picked up either with or without that. I'm adding the config file to the `HOUDINI_PATH` alongside `hopmanager.pref` which is working correctly.
Is it possible to set global defaults for this dialog? I'm currently working on Houdini 19.5.682.
Thanks,
Jon
Technical Discussion » Material assignment for each piece question.
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- Alan S Johnson JR
- 1 posts
- Offline
Asking for some help here.
In Autodesk Maya, there is a bonus tool, that allows you to create a material for each object selected, you can import an .obj or .fbx that has multiple objects or pieces and separate the mesh into separate geometry, then select them all and add a material for each object. It's very useful when you export to .obj or .fbx for use with Unity, UE5, Element 3d, Helium etc to create an assortment of animated effects.
I am trying to create a for each loop that will assign a readable "basic material" for each piece in either .obj or .fbx
it's very unclear to me, from what I can search online how to achieve this in Houdini 19.5.
Can anyone here help me to understand and create a system that will create a material for each piece/object?
the objective is that when I export the model .obj or .fbx, and I import it into any of the above, it reads a material for each object/piece.
In Autodesk Maya, there is a bonus tool, that allows you to create a material for each object selected, you can import an .obj or .fbx that has multiple objects or pieces and separate the mesh into separate geometry, then select them all and add a material for each object. It's very useful when you export to .obj or .fbx for use with Unity, UE5, Element 3d, Helium etc to create an assortment of animated effects.
I am trying to create a for each loop that will assign a readable "basic material" for each piece in either .obj or .fbx
it's very unclear to me, from what I can search online how to achieve this in Houdini 19.5.
Can anyone here help me to understand and create a system that will create a material for each piece/object?
the objective is that when I export the model .obj or .fbx, and I import it into any of the above, it reads a material for each object/piece.
Technical Discussion » How to acces P attribute for arnold shader in Solaris?
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- krahlguru
- 1 posts
- Offline
I have a Solaris Scene, with a Material Library, and i want to shade my geometry based on the position of the points. For Arnold i can use user_data_rgb to read vector attributes like DisplayColor. But i cant acces the P attribute. Why is that, and what do i do about it? As i understood, the desired data is now stored in the primitive "points" because of solaris, is that right?
I would be super grateful for help, im kinda stuck and it seems like a super simple thing to do /:
I would be super grate
Houdini Lounge » How to change position of Floating Operator Chooser?
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- Terence Ziegler
- 46 posts
- Offline
Is there a way to have the default floating window open in the middle of the screen? As opposed to the far upper right, if that's where you click on the Floating Operator Chooser button.
Thanks!
T
Thanks!
T
Technical Discussion » Houdini 19.5 NORMAL text spamming
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- rohankhanalshsr
- 1 posts
- Offline
Can anyone help me with removing the the annoying NORMAL text spamming all across my Houdini screen. I mean where ever I click I see that text. The version is 19.5. I tried reinstalling houdini but it still wont go away. HELP!!!
Solaris » Single Sided Light Switch Does Nothing
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- GlennimusPrime
- 78 posts
- Offline
Hello, I'm using a cylinder light and cannot make it double sided.
I've found and un-checked the 'Single Sided' switch on the Karma tab of the light with no result.
Is there something else I'm missing?
I've found and un-checked the 'Single Sided' switch on the Karma tab of the light with no result.
Is there something else I'm missing?
Technical Discussion » Camera Parameters from Maya to houdini
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- MarXindia
- 32 posts
- Offline
Hello, I received an Alembic camera animated in Maya. The animators animated the flimTranslateH and filmTranslateV parameters along with filmRoll value parameter to create camera shake,since these parameters do not physically transform the camera ,when imported this into Houdini I am not getting the shake(just getting the base transform), I tried to transfer the filmTranslateH and filmTranslateV parameters into winx and winy parameters,which gave me the shake but doen`t match the maya output accurately and has some noticeable offset.Is there anyway to transfer these attributes into Houdini successfully?
Technical Discussion » Karma adds extra folder to output?
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- The3DStig
- 126 posts
- Offline
Sorry for what I suspect is total noob question/issue.
I've managed to get my lopnet exporting to USD files for rendering with Husk via Deadline.
However...
Somewhere along the way an extra directory or two are added to my output path- these don't exist so then Deadline fails the job. If I add said missing directories, it works just fine.
The path "render/3D_render" gets added.
So, if I set Output Picture to "$HIP/test_render" the workers end up looking for "$HIP/test_render/render/3D_render"
I can't figure out where this is coming from, any suggestions or ideas?
I know the easy fix is to just add those directories my file structure or figure out how to let the worker nodes write missing directories (that seemed to work with Mantra?) but I'd like to better understand what's going on and what I'm doing wrong.
Thanks!
I've managed to get my lopnet exporting to USD files for rendering with Husk via Deadline.
However...
Somewhere along the way an extra directory or two are added to my output path- these don't exist so then Deadline fails the job. If I add said missing directories, it works just fine.
The path "render/3D_render" gets added.
So, if I set Output Picture to "$HIP/test_render" the workers end up looking for "$HIP/test_render/render/3D_render"
I can't figure out where this is coming from, any suggestions or ideas?
I know the easy fix is to just add those directories my file structure or figure out how to let the worker nodes write missing directories (that seemed to work with Mantra?) but I'd like to better understand what's going on and what I'm doing wrong.
Thanks!
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