Noise and Siggraph papers

Started by neon22, July 25, 2011, 09:05:31 PM

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neon22

Two of special interest (perhaps) to TG2.
Filtering solid Gabor Noise
http://portal.acm.org/citation.cfm?id=1964946
some info (video) and cpp files can be found here
http://graphics.cs.kuleuven.be/publications/LD11FSGN/
QuoteSolid noise is a fundamental tool in computer graphics. Surprisingly, no existing noise function supports both high-quality antialiasing and continuity across sharp edges. In this paper we show that a slicing approach is required to preserve continuity across sharp edges, and we present a new noise function that supports anisotropic filtering of sliced solid noise. This is made possible by individually filtering the slices of Gabor kernels, which requires the proper treatment of phase. This in turn leads to the introduction of the phase-augmented Gabor kernel and random-phase Gabor noise, our new noise function. We demonstrate that our new noise function supports both high-quality anti-aliasing and continuity across sharp edges, as well as anisotropy.

Temporal light field reconstruction for rendering distribution effects
http://portal.acm.org/citation.cfm?id=1964950
html starter here: http://groups.csail.mit.edu/graphics/tlfr/
QuoteTraditionally, effects that require evaluating multidimensional integrals for each pixel, such as motion blur, depth of field, and soft shadows, suffer from noise due to the variance of the high-dimensional integrand. In this paper, we describe a general reconstruction technique that exploits the anisotropy in the temporal light field and permits efficient reuse of samples between pixels, multiplying the effective sampling rate by a large factor. We show that our technique can be applied in situations that are challenging or impossible for previous anisotropic reconstruction methods, and that it can yield good results with very sparse inputs. We demonstrate our method for simultaneous motion blur, depth of field, and soft shadows.

Tangled-Universe

#1
Hey that's cool, since I started a similar thread at the alpha forums regarding research which could be useful for TG2-integration.
Unfortunately so far with zero interest from PS or anybody else.
Glad to see somebody here is thinking along as well. It's needed, hard.
I'll drop a couple of links of that topic here:

Micro-polygon rendering on GPU:

http://www.kunzhou.net/2010/mptracing.pdf
http://graphics.stanford.edu/~kayvonf/research/index.html (probably suitable for displacement as well)

Volume based surfaces to create caves/arches and such:

http://liris.cnrs.fr/~apeytavi/publications/articles/EG2009_ArchesAFrameworkModelingComplexTerrains.pdf

Another interesting research on a new ray tracing scheme which is able to handle highly complex geometry modeled by the approach of surface patches tessellated to micro-polygons:

http://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.100/institut/Papers/lensch/GI2010-rayReordering.pdf

Clearly, in the past 2-3 years major development took place in the field of rendertime displacement processing of GPU.
Besides that also improvements in ray tracing algorithms have been improved which can deal better with displacements.
Together these developments are something which can't be ignored anymore and need to be seriously investigated/considered.

Neon22, very interesting link about "Temporal light field reconstruction for rendering distribution effects".
I remember another paper from a couple of years ago which showed something similar where very few AA samples were needed to get results close to the ground state. Both motion blur and DoF would strongly benefit from this. Not to mention rendertimes, because you'll need low AA settings for smooth motion blur.
Unfortunately I can't remember the author's name or paper's name anymore, perhaps this one is from the same guys. Need to check out.
PS was also interested back then, but despite recent discussion with PS it seems the interest isn't being pursued further anymore.

If anyone knows more interesting research papers then don't hesitate to post them here.
It's good to bring it under attention since the volume of research papers is quite massive and something useful can be easily missed, but also it might help to push things a bit more in development ;)

Cheers,
Martin

inkydigit

very interesting, I read the one on volume based surfaces after you posted that at the alpha base, Martin - looks great, haven't had time to read the others in any detail...but will definately check them out...
cheers
J

goldfarb

thanks for the Volume based surfaces pdf...interesting stuff...
Houdini has a volume type that can be surfaced - arches etc are really easy - but the rock making technique is pretty cool...
--
Michael Goldfarb | Senior Technical Director | SideFX | Toronto | Canada

neon22

Quote from: Tangled-Universe on July 26, 2011, 03:38:14 AM
...   Volume based surfaces to create caves/arches and such:
http://liris.cnrs.fr/~apeytavi/publications/articles/EG2009_ArchesAFrameworkModelingComplexTerrains.pdf
...

Gosh - Somehow I missed that one. Eurographics huh... I'm missing Siggraph this year - instead I'll be at Digital Earth 2020 in Perth. Only missed a couple in 25 years... oh well

Wouldn't TG2 be amazing with material stacks as defined in that paper. Even just using Rocks and ignoring their refinements for sand etc - which TG2 covers with its surface layers etc...

Seems like it could be implemented as a kind of heightfield node with a thickness and a 2D painted shader for each layer. In fact that's almost exactly what they describe...
Stabilization would be a kind of smoothing operator and just like compute terrain in operation.

I kind of like their idea of using voronoi cells to layer fake stones also but I suspect its not required...

It would also make great curling waves with the addition of code to generate horizontal slices of the wave (and probably animatable)  = now that would be very very cool indeed...
Hmmm...

Oshyan

#5
It's not that there's lack of interest, but we only have so much development resource and there's a long list of awesome, important potential features and improvements. If we chose to implement all these promising sounding new techniques that come up in research papers, we'd have to put aside development work on animation functionality, further improvements to the 3D preview, etc. They're tough choices to make, we just have to pick what we think is the best use of time and resources, for maximum benefit of all users. If you asked 100 users you'd probably get at least 20 different answers as to what should be a priority.

In regards to the previous AA research paper, we did look into it fairly closely and found in fact that it had a very high post-render calculation cost, so while it would make a noticeable difference when using very high AA already (because the calculation time for high quality AA exceeded the post-render calculation times for the technique described), for more average AA levels it would actually have been slower. Often times promising-sounding research turns out to not be so useful in practice on a *broader* range of real-world problems or in an actual product.

Given those kinds of issues, it's probably not surprising that we're not the only ones who can't (or don't) jump on every novel technique. Autodesk has tremendous dev resources, but I doubt you'll see any of these techniques implemented for years, if ever. Likewise with ChaosGroup and Vray, or nVidia and MentalRay.

All that being said we absolutely continue to keep an eye on the ongoing research that's out there and even when we don't implement something directly, we often learn something from it.

- Oshyan

Tangled-Universe

Hi Oshyan,

This had to come out some day, the day is now ;)

A bit strange for me to read now that the AA-filter paper didn't work out because of a very high post-render calculation cost.
We spoke about it about a week ago and even though I didn't knew the authors/paper title anymore it didn't ring any bell.
Consequently, I don't think it is unreasonable for me to think and say it hasn't been pursued anymore, otherwise a bell would have ringed. See?
Regardless of that, it's good that it has been investigated and it's a pity it didn't work out. That happens.

I think the majority of us is aware about novel technologies possibly not being suitable for implementation.
Otherwise tons of silly references would have already been posted.
However, I strongly disagree with the connection you make between the attempt to integrate the AA-filter (just for example) which didn't seem to be suitable and the fact that other companies also can't jump onto novel technologies because of similar situations.
These companies sometimes even developed those novel technologies themselves.
Nvidia invented CUDA and layed down the path for GPU-based rendering.
Chaosgroup with Vray, but also other companies jumped on the CUDA-train and developed applications at sometimes tremendous speed and with as much financial and human resources as PS, maybe even less.
Besides that if you just compare their oldest versions, they are speed- and quality-wise extremely superior to TG2.
Render with AA12 in TG2 and your trees still look CG/game like and it takes an era figuratively speaking.
So in that regard the raytracing implementation is very basic, rough and perhaps outdated. It certainly "feels"/looks like it's outdated.

"Our" biggest competitor Vue already has the volumetric surfaces, for instance. For years.
Besides that some parts of the renderer, like AA, already have been ported to GPU. It's extremely unlikely they will keep it at AA only.
The majority is also aware about resources, but PS cannot keep up using that as the main reason for lack of development and the main reason why others can do that. (We're all here, as customers, aren't we?)
It certainly has to do with ambition and priorities. And with priorities I do not mean the choices which are made during development-time. I think you know exactly what I mean with this ;)
Response to an early suggestion I made well over a year ago was literally "meh...too much math" which makes it evident for me this is the issue. Whether the response was meant sarcastically or not, in both ways it isn't showing enthusiasm and ambition, nor upright interest.

The reason this pops up now is because... how long is TG2 around? 5 years?
How much has changed, significantly? For 5 years people are doing the same thing, dealing with same workflow (of solving issues, design problems as consequence of workflow/issues).
Some of us (pioneers) here who with Matt, you and many others made this community a damn nice place, actually left TG2 for this.
Interest drops as nothing significant changes which makes TG2 much more pleasant to work with in many different ways.
Something with kids and toys, you see.
"You know you have that too, that once in a while for a couple of months TG2 just doesn't work for you anymore. Always the same issues with lack of freedom in design, the extreme effort for really pleasant images, slow, ugly results despite the tons of epxerience with it" to loosely quote from an e-mail I recieved last week as a reply to my question why I don't see him here anymore.
I can admit I have the same experience/feelings. If TG2 would progress more, faster it certainly would allow me to do more, better, beautiful and thus it would be interesting a lot lot longer.

And yes, we all users have our ideas on how and what :)
Now you're essentially saying "If you asked 100 users you'd probably get at least 20 different answers as to what should be a priority" and "thus it's more useful we think of our strategy ourselves(, because the feedback we get is not conclusive or helpful (enough))".
And that's just plain wrong if you would ask me.

In the end I think it really has to do with ambition and priorities and not resources alone.
To get back to Vue, the changes they made, how crap some might be technically, they DO it and GO for it. Especially the latter.

Cheers,
Martin

Oshyan

I appreciate your perspective Martin but I just don't think it's as simple or realistic as you seem to state. Different companies achieve different things with different methods, of course, but these methods and decisions don't come without cost of their own. E-On does what they do and Vue is what it is, but they charge a lot more than we do, they have much more strict upgrade policies, many people complain about bugs in new versions and broken features, etc. Vray is what it is, but from studios we've spoken to, for production purposes, Vray is not actually much faster on TG-like scenes, and cannot achieve the same quality for e.g. volumetrics. So there are no "perfect" solutions. If there were I suppose everyone would be using them. Instead we all have to make decisions on trade-offs for our needs.

Planetside and Terragen are also what they are. Within the limitations with which we work, we do the best we can. You have a different perspective than we do in terms of what would be best for Planetside and that's fine. Ultimately we are a (small) business, all of us need to make a living off of this so I think it's pretty clear we have the greatest investment in Planetside and Terragen's success and the most to lose if it fails. I hope that in the future our business decisions will make more sense to you, and of course most of all I hope that you continue to enjoy and use Terragen.

If anything, perhaps this issue speaks to a failure of communication, which I know has been a concern in the past. We've been working on that and I hope you'll agree we've made progress, but there's more work to be done of course. If you felt that past communication about these issues was dismissive, that is not what we would hope to communicate and it's something we'll work to address.

- Oshyan

Tangled-Universe

Hi Oshyan,

I'm glad you appreciate my perspective :) however, I'm not convinced.
It might be more useful for you to read on on the alpha forums, since some discussion developed there as well in the meantime.
Obviously you may feel a bit less restricted there as I may have forced you to answer some uneasy issues, which I didn't really intend to consciously, so my apologies for that :)

Cheers,
Martin

Oshyan

Thanks Martin. It's fine if you don't agree, I just hope you do understand that your input is very valued and your contributions in other ways are very appreciated (e.g. answering questions here, posting example files, etc.). We'll continue the discussion and always try to improve. :)

- Oshyan