Found 16 posts.
Search results Show results as topic list.
Technical Discussion » Stretching UV issue
- mcfx
- 16 posts
- Offline
That would help if I was rendering out of Houdini, but I'll be exporting the geometry to unreal. So I'm looking for a solution to realign the uv.
Technical Discussion » Stretching UV issue
- mcfx
- 16 posts
- Offline
Hi, I have a grid where I am stretching one end outward. I'd expect the UVs to properly align with the point deformation I applied, but in stead they align per triangle. Nurbs gives me the intended result, but I need the polygon version to work. Any solutions for this?
Much thanks!
Much thanks!
Houdini for Realtime » RBD vertex animation subframe interpolation
- mcfx
- 16 posts
- Offline
My slerp code was incorrect. This solved my problem.
https://gist.github.com/mattatz/40a91588d5fb38240403f198a938a593 [gist.github.com]
https://gist.github.com/mattatz/40a91588d5fb38240403f198a938a593 [gist.github.com]
Houdini for Realtime » RBD vertex animation subframe interpolation
- mcfx
- 16 posts
- Offline
Hey, really enjoying the rbd vertex exporter. I want to expand the provided UE4 shader to handle sub frame interpolation. I've got it close, but something is off with the slerp I am applying to my current and next read in quaternion. Couple questions, in the written out texture, I see the channels G & B swapped, and RGB inverted. Is this to offset the world position? If I read this quaternion in as a color and append the the alpha, is it restored as the correct quaterion? I'm including my hlsl custom slerp code. Its not exploding, but definitly not working as intended. Any thoughts? Has someone already cracked this?
Custom HLSL code for slerp:
float dotp = dot(normalize(q1), normalize(q2));
if ((dotp > 0.9999) || (dotp<-0.9999))
{
if (t<=0.5)
return q1;
return q2;
}
float theta = acos(dotp);
float4 P = ((q1*sin((1-t)*theta) + q2*sin(t*theta)) / sin(theta));
P.w = 1;
return P;
Custom HLSL code for slerp:
float dotp = dot(normalize(q1), normalize(q2));
if ((dotp > 0.9999) || (dotp<-0.9999))
{
if (t<=0.5)
return q1;
return q2;
}
float theta = acos(dotp);
float4 P = ((q1*sin((1-t)*theta) + q2*sin(t*theta)) / sin(theta));
P.w = 1;
return P;
Technical Discussion » Alembic export of primitive attributes
- mcfx
- 16 posts
- Offline
Hey, I have couple questions regarding exporting primitives to an alembic cache. I'm losing my primitive's color assignment when I export. I've tried moving Cd from point to prim. Unpacking after reading in the cache. Nothing seems to work. The scene is super simple, packed Polygon sphere copied onto 25000 points with a random color assignments. How can I preserve the color attribute? If I unpack before exporting, the color reads in. Not what I want to do though.
The other question I have, loading the cache is very slow. The file size is nice and small, but it takes quite a while for houdini to work with it. Any tricks for speeding that up?
Much thanks!
The other question I have, loading the cache is very slow. The file size is nice and small, but it takes quite a while for houdini to work with it. Any tricks for speeding that up?
Much thanks!
Technical Discussion » POPs vdb collisionvel
- mcfx
- 16 posts
- Offline
I have complex creature that needs to collide against a particle sim. I need the creature's velocities to transfer across. VDB collisions are fast when using DOPs applying them via a rbdobject (enabling volumes). I can also transfer my creature's velocity, but I need to wire the vdb source geom into the rbdobject as well. This step is roughly 5x slower. It could be avoided if the rbdobject could also sample the velocity on my creature's VDB.
I could advect the sim with the creature's VDB in POPs, but that's inaccurate as I want the velocity at the collision point. If the POPs solver allowed sampling of collision vdb's velocity internally, you'd have a correct velocity sample and it would be applied in the correct sim order. Less nodes, cleaner rigs.
I could advect the sim with the creature's VDB in POPs, but that's inaccurate as I want the velocity at the collision point. If the POPs solver allowed sampling of collision vdb's velocity internally, you'd have a correct velocity sample and it would be applied in the correct sim order. Less nodes, cleaner rigs.
Technical Discussion » Python fastest method to create 10000 points.
- mcfx
- 16 posts
- Offline
Unfortunately that's not possible for what I'm doing. Will have to be entirely python based.
Technical Discussion » Python fastest method to create 10000 points.
- mcfx
- 16 posts
- Offline
I'm looking a better approach than the following. Is there a quick way to create a set of zero's points in python?
for i in range(10000):
geo.createPoint()
for i in range(10000):
geo.createPoint()
Edited by mcfx - Dec. 21, 2017 17:14:39
Technical Discussion » POPs vdb collisionvel
- mcfx
- 16 posts
- Offline
I'm curious why POPs has not integrated sourcing a velocity grid into its solver when providing a collision vdb with velocity grid (collisionvel). Ideally I want to simplify a setup by providing a single collision source and not include geometry. Has anyone hacked the solver using a sourcevolume?
Technical Discussion » Passing python class objects between python sops
- mcfx
- 16 posts
- Offline
Hey, I have a python class object I am defining within a python sop. I'd like to pass this object further down my sop stream and access it later in another python sop. Is it possible to pack python objects into the stream? I was looking into user data, but that seems more for specific attributes and not data sets.
Much thanks!
Much thanks!
Technical Discussion » Sop material override with per particle colors
- mcfx
- 16 posts
- Offline
Hey, this may not be possible, but I have a material override applied to an object that I am instancing the. The material override is applied at the sop level of the object. That way I can assign per primitive materials, settings.
I want to vary the color of my instance passing the point color through the instance node. I can't seem to do this and assume its because my material override is applied at the sop level.
I've tried adding the following to my material's base color and material override's base color. No luck.
point(“/obj/instance1/OUT”, instancepoint(), “Cd”, 0)
If I remove the sop level material override and place the material on either the instance object at object level or my instance node, the color comes through. Is there some kind of work around I could implement?
Much thanks!
I want to vary the color of my instance passing the point color through the instance node. I can't seem to do this and assume its because my material override is applied at the sop level.
I've tried adding the following to my material's base color and material override's base color. No luck.
point(“/obj/instance1/OUT”, instancepoint(), “Cd”, 0)
If I remove the sop level material override and place the material on either the instance object at object level or my instance node, the color comes through. Is there some kind of work around I could implement?
Much thanks!
Edited by mcfx - Feb. 21, 2017 14:41:04
Technical Discussion » Adding additional inputs to an existing otl.
- mcfx
- 16 posts
- Offline
Hey, is it possible, perhaps by script, to add additional inputs to an already existing otl? Kind of like a subnet. The otl I have has only one input.
Thanks!!
Thanks!!
Technical Discussion » No spec, distant light or point light
- mcfx
- 16 posts
- Offline
Hey, what am I missing. I'm not getting a spec from my distant light. Sphere + default mantra srf, diffuse off, + distant light. No spec in the render.
I've confirmed this setup works fine in H14, H15 seems to be computing things differently. Anyone have a solution?
Thanks!!
I've confirmed this setup works fine in H14, H15 seems to be computing things differently. Anyone have a solution?
Thanks!!
Technical Discussion » Disable .rat auto conversion?
- mcfx
- 16 posts
- Offline
Thanks. Good to know.
If you set your render statistics verbosity to 3, you'll see the image conversions.
If you set your render statistics verbosity to 3, you'll see the image conversions.
Technical Discussion » Possible Memory Issue with the Instance Node Houdini 15
- mcfx
- 16 posts
- Offline
Hey, hit what looks to be a potential memory leak with the instance node in h15.0.292.
Simple scene instancing boxes, check the view port mem use in the performance monitor and loop the play back. The viewport mem keeps climbing and climbing.
Even if I set on the instance node point instancing to OFF, if the node is visible, the mem will increase. I noticed if my source points are static, the mem holds, but animating the point positions causes the viewport mem to climb during geom construction.
Anyone encounter something like this?
Thanks!
Simple scene instancing boxes, check the view port mem use in the performance monitor and loop the play back. The viewport mem keeps climbing and climbing.
Even if I set on the instance node point instancing to OFF, if the node is visible, the mem will increase. I noticed if my source points are static, the mem holds, but animating the point positions causes the viewport mem to climb during geom construction.
Anyone encounter something like this?
Thanks!
Technical Discussion » Disable .rat auto conversion?
- mcfx
- 16 posts
- Offline
Hi, I've noticed houdini is forcing all of my textures into the .rat format. Is there a way to disable this behavior? Are there texture formats that I can use that will bypass this step? tiff, txr, exr?
Thanks!
Thanks!
-
- Quick Links