AccuRender nXt

advanced rendering for AutoCAD

Coming soon-- path tracer only.  Architectural applications are probably limited-- but it's interesting new territory anyway.


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Here's a blend of SSS and procedural marble:


Will do well in certain ceramic tiles


There is very well function of nxt, thank you! :-)

Here's a different use of a similar technology:

Is that fog I see?
In this case, confined to a box 1 meter high.  Uses subsurface scattering techniques...
What's the point of this technology?
I'm not sure I understand the question.  Do you mean "what are the applications?"
I just want to know what exactly your message means - Subsurface scattering - is it some new funcionality in nXt? What's so special on these pictures? What gives this technology?

There's an ok summary of subsurface scattering on Wikipedia.  It's an industry standard term so there's quite a bit about it out there.  Here's another decent article.


Generally speaking, the lighting in nXt and all previous versions of AR occurs at the surface only.  Subsurface scattering is essentially a volumetric technique, where interactions also occur within the medium.  It's required to accurately model materials which we think of as "translucent".  It's also helpful with materials where the light penetrates the surface a little bit-- such as the marble dragons-- and then scatters on its way out.  The feel of the images above would be very difficult to achieve without this technology.


A similar technique can also be used to model other participating media, such as the ground fog above.  This has a very different feel than previous fog implementations.  The technique can be extended to model non-homogenous participating media-- things like smoke or non-uniform fog (clouds?) etc..


Downside is that it can take a long time to resolve these materials-- accurate simulations almost require a path tracer approach.

Thanks a lot for this explanation. Looks promissing.

BTW. I found the Path Tracer the most interesting and valuable feature of nXt. It gives realy soft light (for the first time in whole AR history). But it's not perfect - it's slow - sometimes even hours and houndreds passes don't fix the noisy areas. I'd like to ask you - are you planning to develope this engine? I think it realy worth it.

It is being developed-- subsurface scattering is an example of this.  I'm working on a stand-alone version of the engine as well.

If you mean-- will the performance improve substantially?-- I don't think so.  I don't have any magic wands to wave at the moment.  One of the things I'm going for with this engine is simplicity.  None of the really technical items matter to the path tracer-- for example: Glossy switches, daylight portals, ambient lighting settings, etc.. have no effect.  The combination of this simplicity and the calculation of more light paths slow the thing down-- quite substantially in the case of interior daylighting.  The above mentioned stand-alone has almost nothing to set.

I'm also investigating another engine that has the potential for even more accurate simulations-- probably a little slower, though.

On the bright side-- computers continue to get faster.




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Roy Hirshkowitz replied to Peter Milner's discussion Soft Shadows
"Anyway-- like I said-- I did find a small bug which was causing some additional noise that wouldn't resolve."
13 hours ago
Roy Hirshkowitz replied to Peter Milner's discussion Soft Shadows
"Of course you'll have to fake reflection..."
13 hours ago
Roy Hirshkowitz replied to Peter Milner's discussion Soft Shadows
"That's as expected-- IORs of 1.0 use a different mechanism since there isn't any refraction or caustic.  It's not a bad strategy if the refraction is negligible in the final image-- as in your case."
13 hours ago
Peter Milner replied to Peter Milner's discussion Soft Shadows
"The IOR of the glass windows does seem to make a difference when using the hybrid engine. The attached images have 4000 passes with the hybrid and 2000 passes with the path tracer. "
14 hours ago
Roy Hirshkowitz replied to Peter Milner's discussion Soft Shadows
"It does seem to be resolving really nicely, in both of these models.  Like, I said, there was a problem here which was likely adding some unresolvable noise.  There will still be some differences remaining in the engines-- don't…"
15 hours ago
Peter Milner replied to Peter Milner's discussion Soft Shadows
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