hi,
i can hand code a shader which writes data to a point cloud, but when i try to use the pcexport node in vops, nothing happens.
anyone have an example network i can riff off of?
thanks,
matthew
Found 24 posts.
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Technical Discussion » writing to point clouds from vops
- atabet
- 24 posts
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Technical Discussion » point cloud based ambient occlusion
- atabet
- 24 posts
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hi,
thanks for the links!
after checking out the code, it seems like these solutions use pt clouds to cache the results (thus increasing performance) but still require raytracing to calculate the occlusion.
am i misreading this statement?
while (pcunshaded(handle, “irrad”))
{
pcimport(handle, “P”, mp); mp = ow_space(mp);
pcimport(handle, “N”, mn); mn = normalize(ow_nspace(mn));
if (fullirradiance)
{
cl = irradiance(mp, mn, “samples”, samples, “bias”, raybias,
“background”, background);
}
else
{
cl = occlusion(mp, mn, “samples”, samples, “bias”, raybias,
“background”, background);
}
xxx = pcexport(handle, “irrad”, cl);
}
It seems that the occlusion call still uses raytracing, and just stores the results into the irradiance point cloud.
I was wondering if there was a solution which did the following:
* sampled points within a cone
* used ptarea to determine the percentage of the cone each point covered
* based occlusion from that
anyhow, im going to try it out
cheers,
matthew
thanks for the links!
after checking out the code, it seems like these solutions use pt clouds to cache the results (thus increasing performance) but still require raytracing to calculate the occlusion.
am i misreading this statement?
while (pcunshaded(handle, “irrad”))
{
pcimport(handle, “P”, mp); mp = ow_space(mp);
pcimport(handle, “N”, mn); mn = normalize(ow_nspace(mn));
if (fullirradiance)
{
cl = irradiance(mp, mn, “samples”, samples, “bias”, raybias,
“background”, background);
}
else
{
cl = occlusion(mp, mn, “samples”, samples, “bias”, raybias,
“background”, background);
}
xxx = pcexport(handle, “irrad”, cl);
}
It seems that the occlusion call still uses raytracing, and just stores the results into the irradiance point cloud.
I was wondering if there was a solution which did the following:
* sampled points within a cone
* used ptarea to determine the percentage of the cone each point covered
* based occlusion from that
anyhow, im going to try it out
cheers,
matthew
Technical Discussion » point cloud based ambient occlusion
- atabet
- 24 posts
- Offline
Technical Discussion » point cloud based ambient occlusion
- atabet
- 24 posts
- Offline
hi,
does anyone know a workflow for computing ambient occlusion from point clouds? prman does this and i really prefer it over ray-tracing. anyone know how?
thanks,
Matthew
does anyone know a workflow for computing ambient occlusion from point clouds? prman does this and i really prefer it over ray-tracing. anyone know how?
thanks,
Matthew
Technical Discussion » Houdini Normal Mapping
- atabet
- 24 posts
- Offline
Hi,
Anyone have experience or know of tutorials detailing how to apply normal maps or bake them within Houdini?
I'm having a lot of trouble finding any information about this.
Thanks,
Matthew
Anyone have experience or know of tutorials detailing how to apply normal maps or bake them within Houdini?
I'm having a lot of trouble finding any information about this.
Thanks,
Matthew
Technical Discussion » Tangent Space in VOPs
- atabet
- 24 posts
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Hi,
Does anyone know how I can translate a world space vector to tangent space in VOPs? I've tried constructing a tangent space matrix, but I don't see what I'd expect (though I'm not the best at math).
Anyone know of an example/tutorial of this?
Thanks,
Matthew
Does anyone know how I can translate a world space vector to tangent space in VOPs? I've tried constructing a tangent space matrix, but I don't see what I'd expect (though I'm not the best at math).
Anyone know of an example/tutorial of this?
Thanks,
Matthew
Technical Discussion » Install on Ubuntu
- atabet
- 24 posts
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well, the thing about intel macs is that they still have plenty of proprietary hardware. simply, enough drivers don't exist for a third party os to really run well. though, this is just what i've heard.
im installing ubuntu linux on my macbook, and will be trying houdini out tonight. ill let you know.
matthew
im installing ubuntu linux on my macbook, and will be trying houdini out tonight. ill let you know.
matthew
Technical Discussion » Houdini on MacBook Linux
- atabet
- 24 posts
- Offline
Hi,
Just figured I'd open up this can of worms and ask if anyone has gotten Houdini running under some type of linux on the new Intel based MacBook.
Thanks,
Atabet
Just figured I'd open up this can of worms and ask if anyone has gotten Houdini running under some type of linux on the new Intel based MacBook.
Thanks,
Atabet
Technical Discussion » Particle life driving shader attributes
- atabet
- 24 posts
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Hey,
Well, instead of calling the attribute emitr, just call it emit, and then declare it as a vector. emitr is simply the first element of the attribute emit. emit contains emitr, emitg, and emitb, each representing a color channel.
also, make sure that in the attribcreate, that you are putting your expressions into the value parameter rather than the default parameter. that's something that really messed me up for a while.
by any chance, if you go to scad, we could just meet up. im often in the grad lab and ive done this override procedure a lot.
cheers,
matthew
Well, instead of calling the attribute emitr, just call it emit, and then declare it as a vector. emitr is simply the first element of the attribute emit. emit contains emitr, emitg, and emitb, each representing a color channel.
also, make sure that in the attribcreate, that you are putting your expressions into the value parameter rather than the default parameter. that's something that really messed me up for a while.
by any chance, if you go to scad, we could just meet up. im often in the grad lab and ive done this override procedure a lot.
cheers,
matthew
Technical Discussion » polywire in renderman
- atabet
- 24 posts
- Offline
Greetings,
I have a problem when using polywire in renderman. The polywire seems to only export correctly when its radius is set to 0.01. Any other value creates errors in the geometry. Also, values smaller than 0.01 all appear the same width. I've also tried scaling the source geometry up, then applying polywire, and then scaling back down. Anyone else encountered this problem? Any work arounds?
Thanks,
Matthew P.
I have a problem when using polywire in renderman. The polywire seems to only export correctly when its radius is set to 0.01. Any other value creates errors in the geometry. Also, values smaller than 0.01 all appear the same width. I've also tried scaling the source geometry up, then applying polywire, and then scaling back down. Anyone else encountered this problem? Any work arounds?
Thanks,
Matthew P.
Technical Discussion » Particle life driving shader attributes
- atabet
- 24 posts
- Offline
Hey Brian,
Here's another option:
You can override any shader attribute by using the attribCreate SOP and calling the attribute the same thing as the shader's attribute. To find out the parameter name (which is often different than its label) simply hover over the attribute if you're using houdini 7.
This works great cause you can than assign different colors to different copies of geometry automatically without using the point command.
Cheers,
Matthew Parrott
Here's another option:
You can override any shader attribute by using the attribCreate SOP and calling the attribute the same thing as the shader's attribute. To find out the parameter name (which is often different than its label) simply hover over the attribute if you're using houdini 7.
This works great cause you can than assign different colors to different copies of geometry automatically without using the point command.
Cheers,
Matthew Parrott
Technical Discussion » Creating Random Curves
- atabet
- 24 posts
- Offline
Hi again,
ok, thanks so much for your help. I have one more question, does anyone know how to attach ricurves to curves in houdini?
Thanks,
Matthew
ok, thanks so much for your help. I have one more question, does anyone know how to attach ricurves to curves in houdini?
Thanks,
Matthew
Houdini Lounge » How to render houdini particle as Ripoint for renderman ??
- atabet
- 24 posts
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Technical Discussion » Creating Random Curves
- atabet
- 24 posts
- Offline
Wow! That's amazing! Never seen ray used before… sorry im a dork, but i love that
Thanks so much
Atabet
Thanks so much
Atabet
Technical Discussion » Creating Random Curves
- atabet
- 24 posts
- Offline
Hi,
Anyone have thoughts on how I can create a random curve. I want to make a big ball of tangled string. I tried using the copy sop attached to an add, but I can't figure out how to take a bunch of points and make a curve from them.
Any suggestions?
Thanks,
Atabet
Anyone have thoughts on how I can create a random curve. I want to make a big ball of tangled string. I tried using the copy sop attached to an add, but I can't figure out how to take a bunch of points and make a curve from them.
Any suggestions?
Thanks,
Atabet
Technical Discussion » prman raytracing
- atabet
- 24 posts
- Offline
hey,
thanks so much! using the * in trace visibility works great, very easy.
thanks,
atabet
thanks so much! using the * in trace visibility works great, very easy.
thanks,
atabet
Technical Discussion » prman raytracing
- atabet
- 24 posts
- Offline
Hi,
So, after looking at the ribs some more, it seems that the ray trace visibility is set on a per-object basis. Is there anyway in houdini to add code directly to the rib? i.e. like a rib box in mtor? Also, I'm just using a shop sop to add my renderman shader. Should I be using rishader sop instead?
thanks,
atabet
So, after looking at the ribs some more, it seems that the ray trace visibility is set on a per-object basis. Is there anyway in houdini to add code directly to the rib? i.e. like a rib box in mtor? Also, I'm just using a shop sop to add my renderman shader. Should I be using rishader sop instead?
thanks,
atabet
Technical Discussion » prman raytracing
- atabet
- 24 posts
- Offline
Hi,
I check that, and it is set properly, but still the raytracing is turned off in the RIB. Any other ideas? Anyone have a working houdini file that renders with prman?
Thanks,
atabet
I check that, and it is set properly, but still the raytracing is turned off in the RIB. Any other ideas? Anyone have a working houdini file that renders with prman?
Thanks,
atabet
Technical Discussion » prman raytracing
- atabet
- 24 posts
- Offline
Hi,
I'm having trouble using raytraced sl shaders within houdini. Inside the rib generated by my prman rop, the following line appears before each object
Attribute “visibility” “integer trace”
Which, obviously, turns raytracing off for each object. Anyone know where the option for this variable is inside houdini?
Thanks,
atabet
I'm having trouble using raytraced sl shaders within houdini. Inside the rib generated by my prman rop, the following line appears before each object
Attribute “visibility” “integer trace”
Which, obviously, turns raytracing off for each object. Anyone know where the option for this variable is inside houdini?
Thanks,
atabet
Technical Discussion » Renderman: Getting houdini point data
- atabet
- 24 posts
- Offline
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