Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: damjan on 2014-06-13, 10:28:10

Title: ray histogramm fusion - is this something?
Post by: damjan on 2014-06-13, 10:28:10
i stumbled upon this paper for siggraph 2014:
http://dev.ipol.im/~mdelbra/rhf/ (http://dev.ipol.im/~mdelbra/rhf/)  (youtube video included)
just curious to hear some thoughts if this really can work as advertised, because the speedups look huge..

Title: Re: ray histogramm fusion - is this something?
Post by: racoonart on 2014-06-13, 11:11:20
That looks quite impressive O_o
Definitely something I want to hear more about, especially Ondras opinion of course.
Title: Re: ray histogramm fusion - is this something?
Post by: maru on 2014-06-13, 11:39:02
I'm not any kind of specialist so what I say might be stupid but isn't this pretty close to rendering hd-cache/light cache (some kind of biased path tracing) with interpolated samples? If yes, then this has to produce some visible bias.
Title: Re: ray histogramm fusion - is this something?
Post by: racoonart on 2014-06-13, 11:51:41
As far as I understand it it's more like "filter out information that is too far from the average". That is pretty different from merging and interpolating samples from different locations (like irradience map samples). So there's not a problem with artifacts but in some scenes (e.g. some little bright lit spot on a wall which would be hit by GI bounces and illuminate a wall on the other side of the room) it filters out subtle "useful" information - but that also happens with the msi threshold.
Title: Re: ray histogramm fusion - is this something?
Post by: racoonart on 2014-06-13, 15:39:03
Oh wait, I think I misread this, the description says:
Quote
Each pixel in the image is characterized by the colors of the rays that reach its surface. The proposed filter uses a statistical distance to compare with each other the ray color distributions associated with different pixels, at each scale. Based on this distance, it decides whether two pixels can share their rays or not.

So, that sounds indeed like some kind of interpolation.

Anyways, It would be awesome for animations. Rendering stuff without pre-baking and such reduced render times is such a cost and time saver that it's even worth some little artifacts if there should be some. For me, it sounds like a way to make pathtracing useful for production ;)
Title: Re: ray histogramm fusion - is this something?
Post by: borisquezadaa on 2014-06-13, 17:26:09
But how it will behave with small details?... seems suitable for large areas of same color at large resolutions...
Title: Re: ray histogramm fusion - is this something?
Post by: damjan on 2014-06-13, 17:45:57
But how it will behave with small details?... seems suitable for large areas of same color at large resolutions...

check the pdf, there are more examples - leaves, grass volumetric effects etc. it seems to work fine. the real question is how it works with textures
Title: Re: ray histogramm fusion - is this something?
Post by: arqrenderz on 2014-06-13, 19:03:25
+1 really interesting