Hey guys
Ive been trying this for a while now, but i still am not able to solve it.
Other than converting a grid to a volume and running a volume analyse sop, how would one calculate curl of velocity on a grid sop using an attribute wrangle.
Ive setup a simple grid and ran it thru a pointvop in which ive just plugged in the output of a curl noise vop into v. Now i just want to calculate the curl of v using just the attribute wrangle using neighbours() vex function.
So far ive managed to calculate the gradient of each v component, but the rest of math i cannot translate to proper code.
Any ideas?
p.s. does anyone have resources how to move from math notations to code
Thanks
Found 37 posts.
Search results Show results as topic list.
Technical Discussion » Calculate Curl on a grid sop using attrwrangle sop
- nosferatu037
- 39 posts
- Offline
Houdini Indie and Apprentice » Houdini on Kubuntu 15.10
- nosferatu037
- 39 posts
- Offline
Finally!
Thanks Andrew! You have saved me logging in and out of different desktops!
Cheers
Thanks Andrew! You have saved me logging in and out of different desktops!
Cheers
Houdini Indie and Apprentice » Houdini on Kubuntu 15.10
- nosferatu037
- 39 posts
- Offline
I have had the same exact issue, and i still havent figured out how to solve it or what the issue is on KDE. I say KDE since houdini runs fine if i try and run it in enlightenment desktop or any other than kde. What i do now, which is annoying as hell, is when i start my laptop, i jump quickly into enlightenment source houdini from the shell there, run sesinetd since for whatever reason it wont run automatically, and then run houdini. As soon as its up i close it and move to kde and run it there and it works. I already submitted this as a bug tho sesi guys said they couldnt reproduce it. Im absolutely sure this has to do with a deamon or process in kde that stops license admin from running or houdini from runnig, tho i havent figured out yet which one it could be.
The problem is that houdini just hangs in the shell, there is no output i tried attaching a debugging process to it but i could not find a single output info that explains what the hell is going on.
I have given up so far since i dont have time to start turning services on and off and to debug linux with houdini to see why it wont run.
Hopefully this will get solved somehow
p.s. i should mention im running houdini on opensuse 13.2
The problem is that houdini just hangs in the shell, there is no output i tried attaching a debugging process to it but i could not find a single output info that explains what the hell is going on.
I have given up so far since i dont have time to start turning services on and off and to debug linux with houdini to see why it wont run.
Hopefully this will get solved somehow
p.s. i should mention im running houdini on opensuse 13.2
Houdini Lounge » do your pyro Viewport Shading ok in h15
- nosferatu037
- 39 posts
- Offline
i think that has to do with the new exposure setting on the light, it could be cranked up way too high and its not affecting the volume or its burning it like crazy
see if by adjusting the exposure on your light anything changes, it seems like as you move the light the exposure has to be readjusted accordingly now in h15
or you could simply just have exposure set to 0 and it should work
see if by adjusting the exposure on your light anything changes, it seems like as you move the light the exposure has to be readjusted accordingly now in h15
or you could simply just have exposure set to 0 and it should work
Houdini Lounge » New Renderman tutorial in Houdini
- nosferatu037
- 39 posts
- Offline
Oh thats cool
Its been a while since i played with 3dlight, ill have to look into it and see how they managed to solve the RIS problem.
Thanks
Its been a while since i played with 3dlight, ill have to look into it and see how they managed to solve the RIS problem.
Thanks
Houdini Lounge » New Renderman tutorial in Houdini
- nosferatu037
- 39 posts
- Offline
That is true, but the latest prman is becoming a bit cumbersome, esp since a move from sl to c++ has complicated writing of the shaders, and separation of REYES vs RIS shaders has also introduced another level of complexity.
At least in houdini when you make a shader or if you use the mantrasurface it will work in micropoly or pbr, where it seems that now you have to use separate shaders in prman.
Also i did test the character from the tutorial in prman with fur, to see how long it takes to render, and it wasnt as fast as mantra in RIS mode.
There is much to be learned from prman for sure, but having mantra integrated into houdini and being as powerful at producing good quality result is big advantage over many other software packages that come with half as good native rendering engines. And then having to rely on additional rendering engines and additional cost of buying them as well as learning them.
At least in houdini when you make a shader or if you use the mantrasurface it will work in micropoly or pbr, where it seems that now you have to use separate shaders in prman.
Also i did test the character from the tutorial in prman with fur, to see how long it takes to render, and it wasnt as fast as mantra in RIS mode.
There is much to be learned from prman for sure, but having mantra integrated into houdini and being as powerful at producing good quality result is big advantage over many other software packages that come with half as good native rendering engines. And then having to rely on additional rendering engines and additional cost of buying them as well as learning them.
Houdini Lounge » New Renderman tutorial in Houdini
- nosferatu037
- 39 posts
- Offline
I still wonder what is the point of using RenderMan in this day and age. Such a cumbersome system.
Well thats exactly the reason why i tried to do the same tutorial in mantra. Not only did it do a wonderful job, it was a great fun playing with the shaders and lights.
And also i dont have a reason to have maya installed, and to use prman.
Houdini Lounge » H14 Python source editor
- nosferatu037
- 39 posts
- Offline
Sublime text editor might help. Its quite a good replacement for python source editor in houdini, and it also has vex syntax highlighting.
http://forums.odforce.net/topic/22129-houdini-exhelp-sublime/ [forums.odforce.net]
http://forums.odforce.net/topic/20148-external-editors-for-editing-python-scripts/page-2 [forums.odforce.net]
http://www.sublimetext.com/ [sublimetext.com]
http://forums.odforce.net/topic/22129-houdini-exhelp-sublime/ [forums.odforce.net]
http://forums.odforce.net/topic/20148-external-editors-for-editing-python-scripts/page-2 [forums.odforce.net]
http://www.sublimetext.com/ [sublimetext.com]
Houdini Lounge » New Renderman tutorial in Houdini
- nosferatu037
- 39 posts
- Offline
Hey guys
Ive stumbled upon a really good tutorial on pixars website, about renderman 18/19.
http://renderman.pixar.com/view/TheGrandTour [renderman.pixar.com]
It seemed like a really cool looking project, and since prman 19 was not out as non-commercial at the time, i thought how easy/difficult would it be to try and do something like that in houdini.
Now im not a lighter or a shader writer, im an fx td, but this really was a challenge for me and an opportunity to play with pbr and shader building, and i have to say i was blown away by how easy it is to set up the shaders and to get the project rolling.
So ive downloaded all the project files and exported them as alembic and started building the shaders and trying to replicate them the same way the tutorial suggests. Since the project files had textures and models, it was only the shader building part and the lighting on my part. The difference also is that in the tutorial they already have the shading models and they would build the shading network, where i had to do everything.
Sometimes mantrasurface was enough, other times i had to build one in shops from scratch.
I also used the delay load archive as well as houdini instancing geo to try and do grass, since fur wasnt cutting it. The curve render is good but renderman has a setting to make the curves appear like they are rounded, which makes the spec look quite different.
Since i wasnt able to reproduce this (i did try some hacks suggested by odforce crew, it became too complicated and wasnt giving me proper results), i modeled couple of strands myself and instanced it. Final grass count was around 50000000 and it took 8 min to start the render. Im guessing writing the ifd maybe?
Also the new fur system is pretty cool, i had to learn how it works tho since ive never used it before.
The guide hair system is great and i managed to replicate the top hair of the character, since guide hairs were provided with proj files. Sometimes i would have trouble to try and find some attributes that are named differently in maya, but what ive concluded is that there should be a help page illustrating how to properly use fur (something like a quick tutorial). I know there are pages in help trying to do this, however its split on per fur tool basis, and i was kinda looking more for one page to go over every tool, since i would have to navigate back and forth a lot to try and get to information i needed. And i side navigation bar would help quite a lot in help
The rock shader with moss was a fun thing to do, and ive concluded that there is no way that mantrasurface shader can by default provide an ubersystem solution. Multiple times i found myself wanting to have a way to hook a ramp or a noise patter onto a parameter without diving inside and digging thru the connections.Other times i would simply find the guts of the shader too messy and spending more time finding where i should hook something up, so i would just create a shader from scratch. And the mantrasurface model did provide me with enough inside information to figure out how everything worked, so that was very good.
Ive stumbled across some bugs in the meantime and informed sesi thru RFE about them, such as zbrush tangent vector displacement.
All in all it was extremely fun, and very rewarding i would think to go thru this project, and i got to learn some new stuff as well.
Thumbs up for SESI how much they have improved the entire system, tho there is still work to be done. (default ptex map loading in mantrasurface doesnt work due to links from uv)
Here are some images i managed to render let me know what you guys think (i dont know if this should be in WIP section, if so admins please move it):
Ive stumbled upon a really good tutorial on pixars website, about renderman 18/19.
http://renderman.pixar.com/view/TheGrandTour [renderman.pixar.com]
It seemed like a really cool looking project, and since prman 19 was not out as non-commercial at the time, i thought how easy/difficult would it be to try and do something like that in houdini.
Now im not a lighter or a shader writer, im an fx td, but this really was a challenge for me and an opportunity to play with pbr and shader building, and i have to say i was blown away by how easy it is to set up the shaders and to get the project rolling.
So ive downloaded all the project files and exported them as alembic and started building the shaders and trying to replicate them the same way the tutorial suggests. Since the project files had textures and models, it was only the shader building part and the lighting on my part. The difference also is that in the tutorial they already have the shading models and they would build the shading network, where i had to do everything.
Sometimes mantrasurface was enough, other times i had to build one in shops from scratch.
I also used the delay load archive as well as houdini instancing geo to try and do grass, since fur wasnt cutting it. The curve render is good but renderman has a setting to make the curves appear like they are rounded, which makes the spec look quite different.
Since i wasnt able to reproduce this (i did try some hacks suggested by odforce crew, it became too complicated and wasnt giving me proper results), i modeled couple of strands myself and instanced it. Final grass count was around 50000000 and it took 8 min to start the render. Im guessing writing the ifd maybe?
Also the new fur system is pretty cool, i had to learn how it works tho since ive never used it before.
The guide hair system is great and i managed to replicate the top hair of the character, since guide hairs were provided with proj files. Sometimes i would have trouble to try and find some attributes that are named differently in maya, but what ive concluded is that there should be a help page illustrating how to properly use fur (something like a quick tutorial). I know there are pages in help trying to do this, however its split on per fur tool basis, and i was kinda looking more for one page to go over every tool, since i would have to navigate back and forth a lot to try and get to information i needed. And i side navigation bar would help quite a lot in help
The rock shader with moss was a fun thing to do, and ive concluded that there is no way that mantrasurface shader can by default provide an ubersystem solution. Multiple times i found myself wanting to have a way to hook a ramp or a noise patter onto a parameter without diving inside and digging thru the connections.Other times i would simply find the guts of the shader too messy and spending more time finding where i should hook something up, so i would just create a shader from scratch. And the mantrasurface model did provide me with enough inside information to figure out how everything worked, so that was very good.
Ive stumbled across some bugs in the meantime and informed sesi thru RFE about them, such as zbrush tangent vector displacement.
All in all it was extremely fun, and very rewarding i would think to go thru this project, and i got to learn some new stuff as well.
Thumbs up for SESI how much they have improved the entire system, tho there is still work to be done. (default ptex map loading in mantrasurface doesnt work due to links from uv)
Here are some images i managed to render let me know what you guys think (i dont know if this should be in WIP section, if so admins please move it):
Technical Discussion » Per particle collision in FLIP
- nosferatu037
- 39 posts
- Offline
Thanks Jeff
I thought it was a long shot, but i still wanted to know what you guys have to say.
I thought it was a long shot, but i still wanted to know what you guys have to say.
Technical Discussion » Per particle collision in FLIP
- nosferatu037
- 39 posts
- Offline
Hey guys
I have a question about per particle collisions in flip.
How easy is it to set something like this up.
Say i have an emittter that emits into a flip container and i have two objects that the particles can collide with, along with the ground plane. On the particles i have an attrib that can be either 0 or 1, and based on that attribute the particles either collide with the first or the second object.
I know how to set something like this up in pops however im not entirely sure how one would go about setting something like this on a FLIP sim.
I can attach a simple scene if this doesnt make sense, but it would be very helpful if someone has an idea.
Thanks
I have a question about per particle collisions in flip.
How easy is it to set something like this up.
Say i have an emittter that emits into a flip container and i have two objects that the particles can collide with, along with the ground plane. On the particles i have an attrib that can be either 0 or 1, and based on that attribute the particles either collide with the first or the second object.
I know how to set something like this up in pops however im not entirely sure how one would go about setting something like this on a FLIP sim.
I can attach a simple scene if this doesnt make sense, but it would be very helpful if someone has an idea.
Thanks
Technical Discussion » PTex and Alembic
- nosferatu037
- 39 posts
- Offline
No one has a solution for this?
This is actually an issue (unless im doing something wrong), because if you dont have access to the original maya file, and all you have is alembic with ptex textures, houdini will not render it properly.
Can any devs maybe let me know if i should log this as a bug or RFE.
thanks
This is actually an issue (unless im doing something wrong), because if you dont have access to the original maya file, and all you have is alembic with ptex textures, houdini will not render it properly.
Can any devs maybe let me know if i should log this as a bug or RFE.
thanks
Technical Discussion » PTex and Alembic
- nosferatu037
- 39 posts
- Offline
Hey guys
I have a workflow question.
Im trying to render out alembic file that has vector displacement and diffuse ptex texture, and i cannot get the prim order number correctly.
When alembic node is set to alembic delay load prmitives, the rendered image doesnt load the ptex textures properly.
I tried setting the the alembic to load houdini geometry without polysoups, thinking that it cannot access the prim numbers, and it still has issues. So i tried exporting the first frame of the animation as an obj from maya, and trying that file instead, and it worked perfectly.
If i compare the prim numbers from the obj file vs the alembic file (when loaded as houdini geo) i can see that the order is not the same, which makes the ptex loading problematic.
I guess the only workflow i have for now is to export the alembic animation from maya, and to export first frame of the same geo as a obj file as well, and then inside houdini thru a wrangle node, transfer P from alembic file into P of obj file.
Now it could be that i dont know the proper workflow, but it would help if someone can tell me if im doing something wrong, or if thats the way alembic works.
thanks
I have a workflow question.
Im trying to render out alembic file that has vector displacement and diffuse ptex texture, and i cannot get the prim order number correctly.
When alembic node is set to alembic delay load prmitives, the rendered image doesnt load the ptex textures properly.
I tried setting the the alembic to load houdini geometry without polysoups, thinking that it cannot access the prim numbers, and it still has issues. So i tried exporting the first frame of the animation as an obj from maya, and trying that file instead, and it worked perfectly.
If i compare the prim numbers from the obj file vs the alembic file (when loaded as houdini geo) i can see that the order is not the same, which makes the ptex loading problematic.
I guess the only workflow i have for now is to export the alembic animation from maya, and to export first frame of the same geo as a obj file as well, and then inside houdini thru a wrangle node, transfer P from alembic file into P of obj file.
Now it could be that i dont know the proper workflow, but it would help if someone can tell me if im doing something wrong, or if thats the way alembic works.
thanks
Technical Discussion » Linux houdini floating windows
- nosferatu037
- 39 posts
- Offline
Hey guys
Im wondering if i can get the h13 windows behaviour on linux.
Currently on kde using h14, when creating a floating window, it shows up in the taskbar as another window, which becomes annoying on two screen setup.
Previously on h13, if i have a floating window, when i minimize/maximize both windows obey the same behaviour and houdini main window as well as the floating one are under one taskbar entry.
Currently every single child window i open, whether it be a floating parameter or expression window, they all start crowding my taskbar and it gets really frustrating alt+tabing thru all of them and finding them.
I know maya has this env var MAYA_SET_PARENT_HINT that defines whether floating windows are a part of the main one, and grouped, or if they get individual treatment in the taskbar.
Im not sure if we have control over that in h14?
Thanks
Im wondering if i can get the h13 windows behaviour on linux.
Currently on kde using h14, when creating a floating window, it shows up in the taskbar as another window, which becomes annoying on two screen setup.
Previously on h13, if i have a floating window, when i minimize/maximize both windows obey the same behaviour and houdini main window as well as the floating one are under one taskbar entry.
Currently every single child window i open, whether it be a floating parameter or expression window, they all start crowding my taskbar and it gets really frustrating alt+tabing thru all of them and finding them.
I know maya has this env var MAYA_SET_PARENT_HINT that defines whether floating windows are a part of the main one, and grouped, or if they get individual treatment in the taskbar.
Im not sure if we have control over that in h14?
Thanks
Technical Discussion » icons not showing up houdini 12.5 opensuse 12.3
- nosferatu037
- 39 posts
- Offline
Wolfwood
Might be because Houdini is picking up the system's Python 2.7 libraries instead of its own.
Try setting-
export HOUDINI_PYTHON_BIN=$HFS/python/bin/python2.6
export HOUDINI_PYTHON_LIB=$HFS/python/lib/libpython2.6.so
In your bashrc assuming $HFS is defined at that point.
Thanks wolfwood that was the issue.
AS soon as i set the houdini python env everything strated working fine.
cheers
Technical Discussion » :!: houdini 12.5 on opensuse 12.3
- nosferatu037
- 39 posts
- Offline
Hey guys
I managed to install opensuse 12.3 on my machine and ive downloaded houdini 12.5 and installed it, however i do have quite a lot of problems running it.
Ive started a thread about the icon issues, but it seems that its not the only problem.
It seems that when i load houdini_setup_bash and run houdini all the other applications in -$HFS folder are not getting the env variable properly.
The only way i managed to run houdini with proper loading of icons is if i su and change the hsvg bash script and substitute $HFS with /opt/hfs.x.xxx, so an absolute path
I also cannot run mplay from houdinii to open or flipbook to work.
Houdini just hangs until i hit esc and it takes a while for it to register the key, and in console i get a msg
Spawn Error: : No such file or directory
Error running mplay
Argument list:
0: mplay
1: -flipbook
it seems that mplay.sh is not being executed properly.
This happens if i run houdini by clicking on the icon or if i run it from console.
Can someone help me figure this one out.
cheers
I managed to install opensuse 12.3 on my machine and ive downloaded houdini 12.5 and installed it, however i do have quite a lot of problems running it.
Ive started a thread about the icon issues, but it seems that its not the only problem.
It seems that when i load houdini_setup_bash and run houdini all the other applications in -$HFS folder are not getting the env variable properly.
The only way i managed to run houdini with proper loading of icons is if i su and change the hsvg bash script and substitute $HFS with /opt/hfs.x.xxx, so an absolute path
I also cannot run mplay from houdinii to open or flipbook to work.
Houdini just hangs until i hit esc and it takes a while for it to register the key, and in console i get a msg
Spawn Error: : No such file or directory
Error running mplay
Argument list:
0: mplay
1: -flipbook
it seems that mplay.sh is not being executed properly.
This happens if i run houdini by clicking on the icon or if i run it from console.
Can someone help me figure this one out.
cheers
Technical Discussion » icons not showing up houdini 12.5 opensuse 12.3
- nosferatu037
- 39 posts
- Offline
Hey guys
im having problems seeing icons on my nodes, ive tried previous threads on the forum but none of them provided a solution for me.
Does anyone know how to resolve this issue.
This is the console output i get when i run houdini:
linuxopt/hfs12.5.371 # Warning: program compiled against libxml 209 using older 207
Warning: program compiled against libxml 209 using older 207
/opt/hfs12.5.371/hsvg/hsvg: line 7: /hsvg/hsvg-bin: No such file or directory
it seems that houdini is trying to use an older version of the libxml or is linked to different version
im having problems seeing icons on my nodes, ive tried previous threads on the forum but none of them provided a solution for me.
Does anyone know how to resolve this issue.
This is the console output i get when i run houdini:
linuxopt/hfs12.5.371 # Warning: program compiled against libxml 209 using older 207
Warning: program compiled against libxml 209 using older 207
/opt/hfs12.5.371/hsvg/hsvg: line 7: /hsvg/hsvg-bin: No such file or directory
it seems that houdini is trying to use an older version of the libxml or is linked to different version
Technical Discussion » Sop solver problem
- nosferatu037
- 39 posts
- Offline
Managed to make it work
I wasnt checking if the color was changing so i kept overwriting the color on every frame
I wasnt checking if the color was changing so i kept overwriting the color on every frame
Technical Discussion » Sop solver problem
- nosferatu037
- 39 posts
- Offline
Hey guys I have a question about the sop solver.
I looked at the sop solver tutorial and tried to do the same thing (accumulate color on a surface over time) but instead of using attribute transfer to do it i tried vopsop and point clouds to do it, as well as intersection vop.
It seems however that the color wont accumulate if i use anything other then attribute transfer or im doing something wrong.
It does transfer the color on every frame and it does it right but it seems like its not taking into account the prev frame at all.
Can anyone let me know if there is something im missing here?
cheers
I looked at the sop solver tutorial and tried to do the same thing (accumulate color on a surface over time) but instead of using attribute transfer to do it i tried vopsop and point clouds to do it, as well as intersection vop.
It seems however that the color wont accumulate if i use anything other then attribute transfer or im doing something wrong.
It does transfer the color on every frame and it does it right but it seems like its not taking into account the prev frame at all.
Can anyone let me know if there is something im missing here?
cheers
Houdini Lounge » Splash tool not on shelf
- nosferatu037
- 39 posts
- Offline
Hi guys
I've found a splash tool in houdini help but i couldnt find it on the shelf of particle fluids.
Is this supposed to be on the shelf?
I've found a splash tool in houdini help but i couldnt find it on the shelf of particle fluids.
Is this supposed to be on the shelf?
-
- Quick Links