Just in case someone is wondering the samething…
Atom gave me the answer on odforce:
http://forums.odforce.net/topic/31883-bullet-and-flips-collisions/?tab=comments&_fromLogin=1 [forums.odforce.net]
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Technical Discussion » RBD Packed Objects in bullet and FLIP SIMS
- Nicolas Heluani
- 280 posts
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Technical Discussion » RBD Packed Objects in bullet and FLIP SIMS
- Nicolas Heluani
- 280 posts
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Hi,
Can someone please help me confirm is bullet is compatible or not with flip simulations?
I set up a simple packed geo as a static object for a flip simulation.
The geometry collision is properly calculated as convex hulls…
But as soon as I run the sim this weird shape appears:
It is like if the flip sim automatically converts the collision geo into a weird resampled volume.
is this true? Would this mean that the flip solver will automatically convert the packed geo into a volume?
Feel free to look at my set up… I simplified the scene to run a test. (the hip file is attached at the bottom)
Can someone please help me confirm is bullet is compatible or not with flip simulations?
I set up a simple packed geo as a static object for a flip simulation.
The geometry collision is properly calculated as convex hulls…
But as soon as I run the sim this weird shape appears:
It is like if the flip sim automatically converts the collision geo into a weird resampled volume.
is this true? Would this mean that the flip solver will automatically convert the packed geo into a volume?
Feel free to look at my set up… I simplified the scene to run a test. (the hip file is attached at the bottom)
Edited by Nicolas Heluani - Nov. 12, 2017 07:19:25
Technical Discussion » output variables to extra image planes
- Nicolas Heluani
- 280 posts
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Technical Discussion » Generating velocity for motion blur
- Nicolas Heluani
- 280 posts
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I don't know about octane workflow but in mantra and Arnold you need to first calculate a velocity attribute. ( you can do this with a trail sop, set it to calculate velocity. You will need to do this regardless of the render engine as otherwise the render engine has no velocity att to work with.
Then at the obj level you need to check the box that says to use the velocity attribute from points to calculate motion blur.
Nico.
Then at the obj level you need to check the box that says to use the velocity attribute from points to calculate motion blur.
Nico.
Edited by Nicolas Heluani - Oct. 18, 2017 12:51:12
Technical Discussion » output variables to extra image planes
- Nicolas Heluani
- 280 posts
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I am a bit confused? if I have a principle shader and a variable I want to output to an extra image plane….
How do I mix them?
Basically how to I say to mantra to check for this variable aswell?
The second image is what i do ussually in a material builder node… but I was wondering if it is possible to do it outside the material builder?
How do I mix them?
Basically how to I say to mantra to check for this variable aswell?
The second image is what i do ussually in a material builder node… but I was wondering if it is possible to do it outside the material builder?
Edited by Nicolas Heluani - Oct. 17, 2017 10:47:22
Technical Discussion » boolean attributes vs int attributes
- Nicolas Heluani
- 280 posts
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Olaf FinkbeinerThank you very much!
Hi Nicolas,
you can create a 8bit integer attribute for a boolean see:
http://www.sidefx.com/docs/houdini15.0/nodes/sop/attribcast [www.sidefx.com]
regards
Olaf
Technical Discussion » boolean attributes vs int attributes
- Nicolas Heluani
- 280 posts
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Hi,
Does anyone know the reason why there isn't a boolean attribute type in Houdini?
I know you can make one with a simple integer value but the reason behind boolean attributes themselves is for the small footprint. And in houdini we find ourselves often working on the millions of points so any reduction of data helps right?
And I know you can define a boolean with a simple relation with an integer, float or even vector. I was thinking in performance. While a integer value is a 32 bit attribute with a huge range traditionally a boolean attribute is just 1 or 0, very efficient when dealing with huge amount of data.
Maybe a 1 or 0 int is the same footprint as a boolean attribute?
Does anyone know the reason why there isn't a boolean attribute type in Houdini?
I know you can make one with a simple integer value but the reason behind boolean attributes themselves is for the small footprint. And in houdini we find ourselves often working on the millions of points so any reduction of data helps right?
And I know you can define a boolean with a simple relation with an integer, float or even vector. I was thinking in performance. While a integer value is a 32 bit attribute with a huge range traditionally a boolean attribute is just 1 or 0, very efficient when dealing with huge amount of data.
Maybe a 1 or 0 int is the same footprint as a boolean attribute?
Technical Discussion » color in attribute wrangles
- Nicolas Heluani
- 280 posts
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Technical Discussion » color in attribute wrangles
- Nicolas Heluani
- 280 posts
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I love the create spare parameter button. But I was wondering if there is a way to specify a vector is a color directly in vex? Because I set it up with a
and then have to go to the edit parameter interface to specify this vector is a color attribute.
And, yes, I know I am very veryspoiled here …. but wouldn't be cool to be able to specify it is a color parameter so it creates the appropriate slider?
Nico
vector color_param = chv ("color_param");
And, yes, I know I am very veryspoiled here …. but wouldn't be cool to be able to specify it is a color parameter so it creates the appropriate slider?
Nico
Technical Discussion » $PI in @variable...
- Nicolas Heluani
- 280 posts
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Technical Discussion » $PI in @variable...
- Nicolas Heluani
- 280 posts
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I know insanely OCD but it really hurts to see the code like this:
@P.y +=sin(@P.x*$PI/2);
It works but is there an equivalent for PI with the new @ mark?
Nico.
@P.y +=sin(@P.x*$PI/2);
It works but is there an equivalent for PI with the new @ mark?
Nico.
Technical Discussion » snow from sand.... help needed
- Nicolas Heluani
- 280 posts
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Technical Discussion » snow from sand.... help needed
- Nicolas Heluani
- 280 posts
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jsmack
That is a warning, you can normally ignore it. Uniform volume is the wrong material to use for actual density volumes such as vdb. A standard volume shader such as ‘volumeshadercore’ will work. Uniform volume is a fake volume for use with surfaces (polygons or particles as spheres.) Connecting the vdb from particles into the volume rasterize particles is redundant. You only need to rasterize once. Use a vdb sop to create an empty vdb, and connect that to the volume rasterize particles.
Thank you for the help…
I was getting nervous because is my first time rendering volumes in mantra and I thought the error was something to recon. I eventually ended up using a mantra attribute in the geometry that interpret the obj as a uniform volume and render it directly like that without any transformation to VDB. I am interested in actually transforming my particles to VDB for future projects and maybe for other renderers, So your help is really appreciated. I will test it as soon as I am out of this insane deadline. thanks again
Technical Discussion » snow from sand.... help needed
- Nicolas Heluani
- 280 posts
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I try converting the points to vdb and ten applying a uniform smoke but I get this error:
I wish I could share a hip file but the set up is rather complex. to share.
I wish I could share a hip file but the set up is rather complex. to share.
Technical Discussion » snow from sand.... help needed
- Nicolas Heluani
- 280 posts
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I made this cool sim with PBD but now I need to transform those particles into volumes as explained in the masterclass here around 47:42
https://vimeo.com/142534638 [vimeo.com]
I cannot figure out how? He did this. any help?
Bests,
Nico.
https://vimeo.com/142534638 [vimeo.com]
I cannot figure out how? He did this. any help?
Bests,
Nico.
Houdini Learning Materials » Snow or PBD tutorial
- Nicolas Heluani
- 280 posts
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Hi,
Anyone know a good tutorial for snow sims or pbd´s beside the masterclass?
I will be doing a quick sim (by necesity of the deadline) on snow blowing over an object and it will be nice something to refresh the memory.
Anyone know a good tutorial for snow sims or pbd´s beside the masterclass?
I will be doing a quick sim (by necesity of the deadline) on snow blowing over an object and it will be nice something to refresh the memory.
Technical Discussion » ramp curve from -1 to 1
- Nicolas Heluani
- 280 posts
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mestelaThanks, good to know.
No. Values on the vertical axis can go above 1 and below 0, but the graph can't be resized to see it. For now, your expected to normalise your input values.
Technical Discussion » ramp curve from -1 to 1
- Nicolas Heluani
- 280 posts
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I know I can do this by simple multiplication in Vex but is there a way to see the profile of the chramp parameter from -1 to 1 instead of from 0 to 1?
Nic.
Nic.
Work in Progress » Glass Cutter HDA
- Nicolas Heluani
- 280 posts
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i73thanks man but please notice that the HDA is still very incomplete…it needs to be set up so it works on different axis and input geo positions. But that shouldn't be that difficult, I usually leaves those final details until I actually need the HDA for production.
Great idea man, looks great!
Technical Discussion » previewing obj files....
- Nicolas Heluani
- 280 posts
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Thanks everyone for the recommendations.
Indeed the soft I used to use was meshlab, I will check out Open3dMod. Basically I have some heavy scans I would have liked to just preview in a quick way. Meshlab may do the trick.
Indeed the soft I used to use was meshlab, I will check out Open3dMod. Basically I have some heavy scans I would have liked to just preview in a quick way. Meshlab may do the trick.
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