Hello Kai and Sidefx-
We are running into issues with hairgen::2.0 changing point counts with high numbers of hairs (greater than 10,000,000) when the hair is deformed.
Even though we are providing a rest we get 1 or 2 points of variation in a 200 frame animation sequence.
There are settings and orders of operation that seem to make this worse, but I'd like to know if this is something you've seen across the board.
We see this when motion blur fails due to changing topology and it's a bit mind binding to have to add a work around per hairgen.
Kind Regards,
Found 20 posts.
Search results Show results as topic list.
Technical Discussion » Hairgen Point Count Changes with High Numbers of Hair
- mrbag
- 21 posts
- Offline
Technical Discussion » Q: Cloth success?
- mrbag
- 21 posts
- Offline
Technical Discussion » Q: Cloth success?
- mrbag
- 21 posts
- Offline
Probably not news to many, but cloth seems to have improved.
I have been stuck in H10 for a long time and just had a bit of time to test out H11.0.733.
The firsts tests seem promising, even when compared with maya nCloth, which is fantastic.
Here is a simple collision with tearing example:
http://vimeo.com/24410553 [vimeo.com]
Although there are definitely some quirks to using the system, I feel like even this simple test makes for some interesting possibilities.
So, a few basic things I am wondering about. Why do the parameters in the cloth object seem to be resolution specific. For example, a grid of 20x20 and 10x10 do not behave the same with respect to tearing. This is counter intuitive to people who might do a quick test and then start moving up the resolution of the geo.
In maya, it doesn't seem to have this problem. Although, you do have to resetup the entire sim if the geo changes, so maybe there is something in the setup process I am not seeing.
One other request is something like the maya presets. I haven't been doing much in dops these days, so maybe I don't know of a simple way to do this, but making a preset for cloth that behaves like silk, versus rubber seems to cross different nodes if not contexts. Regardless, it would be cool if there was a mechanism for making cloth presets.
Well, hopefully more tests to come. Nice work sesi
I have been stuck in H10 for a long time and just had a bit of time to test out H11.0.733.
The firsts tests seem promising, even when compared with maya nCloth, which is fantastic.
Here is a simple collision with tearing example:
http://vimeo.com/24410553 [vimeo.com]
Although there are definitely some quirks to using the system, I feel like even this simple test makes for some interesting possibilities.
So, a few basic things I am wondering about. Why do the parameters in the cloth object seem to be resolution specific. For example, a grid of 20x20 and 10x10 do not behave the same with respect to tearing. This is counter intuitive to people who might do a quick test and then start moving up the resolution of the geo.
In maya, it doesn't seem to have this problem. Although, you do have to resetup the entire sim if the geo changes, so maybe there is something in the setup process I am not seeing.
One other request is something like the maya presets. I haven't been doing much in dops these days, so maybe I don't know of a simple way to do this, but making a preset for cloth that behaves like silk, versus rubber seems to cross different nodes if not contexts. Regardless, it would be cool if there was a mechanism for making cloth presets.
Well, hopefully more tests to come. Nice work sesi
Technical Discussion » Volumetric Clouds Shading/Lighting
- mrbag
- 21 posts
- Offline
Have you considered an env light with a HDRI containing a bright sun and nice sky. I have had some success lighting volumes with that?
You can control the direction of the sun by rotating the world via the env light. And the extra fill lighting can be somewhat controlled by manipulating the HDRI sky color.
You can control the direction of the sun by rotating the world via the env light. And the extra fill lighting can be somewhat controlled by manipulating the HDRI sky color.
Technical Discussion » group by expression
- mrbag
- 21 posts
- Offline
the texni() combined with a conditional in the group expression field should give you what you want. Something like:
texni(“Mandril.pic”,$MAPU,$MAPV,R)>.5
texni(“Mandril.pic”,$MAPU,$MAPV,R)>.5
Technical Discussion » Rendering shadows
- mrbag
- 21 posts
- Offline
Check out the VEX ShadowMatte shader. Placing this on the grid in your scene and rendering the character as a phantom object you will get the shadow of the character on the grid in the alpha channel of the final image.
I have attached a demo file with take takes in it.
MAIN=>render both the character (sphere) and the grid normally.
SHADOW=>the setup as described above. Check the alpha and you should see the shadow only.
Hope this helps.
I have attached a demo file with take takes in it.
MAIN=>render both the character (sphere) and the grid normally.
SHADOW=>the setup as described above. Check the alpha and you should see the shadow only.
Hope this helps.
Technical Discussion » slow color transfering to particles
- mrbag
- 21 posts
- Offline
Technical Discussion » How to time-offset Filenodes (read)?
- mrbag
- 21 posts
- Offline
Speaking of which, it sure would be nice if Timewarp could use ID natively…HINT, HINT. :idea:
Technical Discussion » Custom Image Planes with PBR
- mrbag
- 21 posts
- Offline
Do you mean constant shaded grids? I think all things must be “lit” to be visible in PBR.
Can you clarify?
Can you clarify?
Technical Discussion » How to time-offset Filenodes (read)?
- mrbag
- 21 posts
- Offline
Check out the SOPs with “time” in the name. Timeshift and Timewarp can be quite handy for this kind of thing.
Work in Progress » WIP: Ocean an ship (splash, &intersection, spray..)
- mrbag
- 21 posts
- Offline
Love your camera in that last post. Very “Master and Commander” (one of my favorites). Keep going!
Houdini Indie and Apprentice » how to export to OBJ?
- mrbag
- 21 posts
- Offline
You can also right click on the SOP and “Save Geometry”. Then make sure the extension is .obj.
Technical Discussion » Large Scale Scenes
- mrbag
- 21 posts
- Offline
Houdini is in general unit agnostic.
It seems like you can use what a project requires or personal preference.
When working with large scales camera clipping planes are a bit wonky and you will have to adjust things accordingly. Same goes for lights if they have any near/far clipping.
At super large or small scales bad things can happen due to numeric precision, but I think sidefx has addressed most of these issues on the rendering side by using double floats for things like camera matrices. Not sure what DOPs will do at those scales.
DOPs does have a setting for units that defaults for length in meters and mass in Kg. It's under the Main Menu->Edit->Preferences->Hip File Options.
Something that often happens to me is I will develop a little test around the origin in meters, but then find out that things are either in CM or US units (feet/inches/etc). I tend to leave the setup alone if its producing nice results and use conversions via global scale parameters and/or parenting hierarchies, rather than rework the entire setup.
It seems like you can use what a project requires or personal preference.
When working with large scales camera clipping planes are a bit wonky and you will have to adjust things accordingly. Same goes for lights if they have any near/far clipping.
At super large or small scales bad things can happen due to numeric precision, but I think sidefx has addressed most of these issues on the rendering side by using double floats for things like camera matrices. Not sure what DOPs will do at those scales.
DOPs does have a setting for units that defaults for length in meters and mass in Kg. It's under the Main Menu->Edit->Preferences->Hip File Options.
Something that often happens to me is I will develop a little test around the origin in meters, but then find out that things are either in CM or US units (feet/inches/etc). I tend to leave the setup alone if its producing nice results and use conversions via global scale parameters and/or parenting hierarchies, rather than rework the entire setup.
Technical Discussion » particle rain.... best rendering tips
- mrbag
- 21 posts
- Offline
I would use copying for visualization, but actually use point instancing for rendering. Much quicker.
Also if you use sprites, you can use the copy sop and/or the sprite sop, but in the end the sprite procedural is much more effecient for large amounts of sprites.
Also if you use sprites, you can use the copy sop and/or the sprite sop, but in the end the sprite procedural is much more effecient for large amounts of sprites.
Technical Discussion » Unable to render with Micropolygon, PBR works fine
- mrbag
- 21 posts
- Offline
Are the objects running through the near clipping plane of the camera? This can cause mantra problems, or has in the past.
When in doubt reduce the problem. Cut the geo down to one instance, then double the numbers until it happens again.
Don't forget you can dump to IFD (turn off binary) and look through it for any weirdness.
When in doubt reduce the problem. Cut the geo down to one instance, then double the numbers until it happens again.
Don't forget you can dump to IFD (turn off binary) and look through it for any weirdness.
Technical Discussion » particle rain.... best rendering tips
- mrbag
- 21 posts
- Offline
Points tend not to light or shadow as well as you would like.
Instanced primitive spheres or even pyramids (platonic solid sop) can be good for heavy downpour, especially if you want to get a shafts of light and shadow.
Sprites can be good for somethings like splashes and overhang runoff.
Metaballs with a convertmeta will give you a surface that can be exactly controlled, like with slow motion rain. For maximum efficiency look into the metaball procedural, as you can polygonize the metas at render time instead of dumping tons of polys to disk.
Instanced primitive spheres or even pyramids (platonic solid sop) can be good for heavy downpour, especially if you want to get a shafts of light and shadow.
Sprites can be good for somethings like splashes and overhang runoff.
Metaballs with a convertmeta will give you a surface that can be exactly controlled, like with slow motion rain. For maximum efficiency look into the metaball procedural, as you can polygonize the metas at render time instead of dumping tons of polys to disk.
Houdini Indie and Apprentice » Help Browser is locking up Houdini
- mrbag
- 21 posts
- Offline
Hey All-
I am in 9.5.175 on Linux and houdini will hang with this problem consistently when the default web browser is already open. If you close the default browser, firefox on my system, and open houdini, *most* of the time your file will open fine.
Also, if you open with your file in “Manual” mode it will not hang most of the time.
Obviously, we can turn off opening the help browser at startup.
I am in 9.5.175 on Linux and houdini will hang with this problem consistently when the default web browser is already open. If you close the default browser, firefox on my system, and open houdini, *most* of the time your file will open fine.
Also, if you open with your file in “Manual” mode it will not hang most of the time.
Obviously, we can turn off opening the help browser at startup.
Houdini Indie and Apprentice » No Middle Mouse Color Sample on Mac
- mrbag
- 21 posts
- Offline
It seems that the middle mouse sample color function is not working on Mac. If you middle mouse on the color swatch widget and you get the sampling cross hairs, but it does not update the color swatch as you move the mouse around.
I am sure I am butchering the proper names of the widgets and functions.
To test this, I switched to the Image desktop, created a compositing network, and a Color node. I tried middling on the color swatch. I have tried this on a shop, a point sop, and a light and consistently the color sampling is not working.
I am sure I am butchering the proper names of the widgets and functions.
To test this, I switched to the Image desktop, created a compositing network, and a Color node. I tried middling on the color swatch. I have tried this on a shop, a point sop, and a light and consistently the color sampling is not working.
Houdini Indie and Apprentice » Installing help
- mrbag
- 21 posts
- Offline
Seems to be the same case with the Mac OS package. On the “Download Apprentice” page the download gives you a file called <file>.dmg.html. This file thoroughly confuses any browser. Renaming it to .dmg results in an unmountable disk image.
On the regular download page you get a file called <file>.dmg which mounts fine.
On the regular download page you get a file called <file>.dmg which mounts fine.
Technical Discussion » hmaster.exe has stopped working
- mrbag
- 21 posts
- Offline
I am running Houdini under Windows Vista. I just purchased Houdini Apprentice HD and got the same errors. I rebooted and restarted windows and everything was fine. Hopefully the same will happen for you.
Maybe there is something funky in the installer on Windows Vista. Or perhaps one of the updates when I restarted fixed something?
Maybe there is something funky in the installer on Windows Vista. Or perhaps one of the updates when I restarted fixed something?
-
- Quick Links