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Instancing support ?!

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Re: Instancing support ?!

Post Sun Mar 06, 2011 8:18 pm

sanderboer, as much as i appreciate the compliment :), this is a team effort, instancing is a joint effort by bert_b a.k.a. _bert and me, even though the commit was made by me.

Sometimes has happened that i commit work done with others, in this case i made the mistake of not crediting the participants correctly, sorry about that :oops: .

And yes in general the small army is composed by 1 to 3 devs at the most in the 2 years i've been a developer here :), in rotation depending on the times of each one. For example the active developers in this moment are bert_b and i :)

Best regards,
Just Vampires Playing To Be Mortals...
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Re: Instancing support ?!

Post Sun Mar 06, 2011 10:19 pm

Rio wrote:I'm on Windows 7 64

Here is a fresh Windows Build: Yafaray Core 0.1.2 (master branch) with exporter for Blender 2.56 (also master branch) and Blender SVN revision 35350:

Bye, Olaf.
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Re: Instancing support ?!

Post Mon Mar 07, 2011 1:24 pm

Thanks Olaf,

Rendering some grass now !

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Re: Instancing support ?!

Post Mon Mar 07, 2011 2:09 pm


You. Are. Awesome.
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Re: Instancing support ?!

Post Mon Mar 07, 2011 4:18 pm

Fully Awesome!!
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Re: Instancing support ?!

Post Mon Mar 07, 2011 7:27 pm

DarkTide wrote:The alpha color on the plane has to do with the way the textures are processed, there is a thread on the forum about that sorry if i don't provide the link but i'm not on my usual box


I know this could be the wrong thread, but let let me tell, what I've found out.
I assume you were thinking about "Alpha Intensity". So i tried out. But with no satisfying result. Later on I switched on the diffuse channel for the alpha-map additionally and that's it.
Maybe a bug ? :roll:

kind regards
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Re: Instancing support ?!

Post Mon Mar 07, 2011 7:52 pm

Just for the fun of it, let me bring down the mood a bit. Since we use a kdtree in YafaRay, the instances don't save as much memory as possible, because each triangle in each instance still needs to be inserted "uniquely" into the kdtree. So there is still no way to render billions of triangles.

Condar told me, that a 58 million triangles scene (I guess the monkeys?) took 6 or 7 GB RAM during rendering and even more during the tree construction. For instancing to really make sense, we would need an acceleration structure that can hold bounding boxes instead of the full objects. One such possibility is a BVH. We'll see.
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Re: Instancing support ?!

Post Tue Jun 28, 2011 11:11 pm

@bert_b There is a much more efficient way to use kd-trees with instancing. Create one local kd-tree around the object in model space. Then, you only need to insert the object's triangles _once_ into its own kd-tree, as all other instances use locally transformed variants of that kd-tree. When you test a ray on an instance, you transform the ray back into model space are reuse the same kd-tree for all of them. For global scene management, it is better (in my opinion) to use a BVH at high-level, with individual kd-trees for objects, which easily applies to instanced objects also (reusing its local kd-trees). This is because polygon details are usually localized in space to individual models with lots of space between them. Thus, BVH gives rapid gains first, followed by detailed traversal of locally oriented kd-trees. This also handles animation much faster, because the local coordinate frames can animate without changing the object kd-tree, so re-insertion is avoided per frame.

I'm a graphics dev doing procedural modeling looking for a renderer to experiment with (hence the need for instancing support).
Is there a build of Yafaray that has instancing now, as the link to 0.1.2 posted earlier in this thread is broken?
Do you know what the XML commands are to do instancing? I look forward to instancing as it is an important feature for putting Yafaray on par with other major renderers. (and maybe even willing to help out)
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Re: Instancing support ?!

Post Wed Jun 29, 2011 12:47 pm

Well, yes, the way you describe this is the way how to do it. I read the papers. We currently lack the global BVH structure with local kdtrees and the corresponding traversal logic.

The builds by megasoft on should contain the instancing features. I'm not sure right now if it's possible to use it via XML, I'd have to look at the exporter. Since you are a dev, you should have no trouble compiling the git version, though.

In my opinion, instancing is essential for certain types of scenes (nature scenes for instance with 1000s of trees) but most scenes don't profit from it.
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Re: Instancing support ?!

Post Sun Sep 25, 2011 10:42 am

I'm testing instances with the "blender-r37411-yafa-luxr-slg" build.

But Blender/Yafaray always crashes when it starts to render:
Bildschirminhalt erfassen-1.jpg

Maybe my scene is to complex for testing.

But maybe you can give me some hints to find the problem ?
Did I understand right: It doesnt matter if I use SPPM or Pathtracing, they both support Particle Instance ?

I've tested both and they both crash. Even if I reduce my scene to the Particle System only with very low settings (1000 Particles, Particleobject is a plane with a grass alphamap).

Kind regards
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Re: Instancing support ?!

Post Sun Sep 25, 2011 11:57 am

Particles were last enabled in May this year:- ... 62e0292a05

Maybe try a more recent build. Particles are working here on a recent build.

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