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Frenetic Pony

Member Since 30 Oct 2011
Offline Last Active Today, 08:24 PM

Posts I've Made

In Topic: Hybrid Frustum Traced Shadows

22 May 2016 - 06:53 PM

Yeah, looking at it again, it just appears to be "Create shadow map like structure, create frustum for each primitive in the shadow map, link onscreen pixels to shadow map texels (list of onscreen pixels as covered by which shadow map texel) then for each pixel, go to shadow map texel it's linked to, then within that texel test against each frustum you constructed to see whether that point (pixel I think) is within the frustum. It's a lot like shadow volumes, but unfortunately seems to involve atomics (mentioned as part of the irregular z-buffer, which creates the linked list of onscreen pixels to shadow map texels) as well as creating frustums and then frustum tests.


None of it by itself is necessarily expensive, but is overall a lot more expensive than just doing a normal shadow map, let alone the virtual shadow map I originally linked to which can be faster than a normal shadow naive cascaded shadow map. Virtual shadow maps will also come close to having a 1 to 1 match to screen resolution, and so will have close to the same quality as this anyway while being a lot more efficient. The only other thing they're doing is comparing unfiltered shadow maps without SMAA applied to their results (With SMAA applied, which has nothing specifically to do with this, cough cough) and frankly no one just uses unfiltered shadow maps and I had to look at the zoomed in portion of their comparison to appreciate the difference anyway.

In Topic: Hybrid Frustum Traced Shadows

21 May 2016 - 05:16 PM

So where does this https://developer.nvidia.com/sites/default/files/akamai/gameworks/Frustum_Trace.jpg fit into what you just described.  Also the how does the irregular z-buffer fit into this?


That's afaik, the ray vs triangle intersection test. You construct your frustum as in the jpeg then test if the onscreen pixel is inside that frustum. Don't remember what the irregular Z-buffer was for, as I glanced through the paper and concluded Sebastian's "virtual shadow mapping" (about 3/4ths of the way down) would serve something similar in terms of image quality while doing so a lot faster.


If you're really going for some "make high end PC stuff useful" as Joe-J suggests I've found just having everything be scaleable in the engine is a good idea anyway. That way you can turn things (SSR/SSAO samples, shadow map res, g-buffer quality, LOD distance/quality, HDR buffer quality, etc.) down and/or up as needed to hit any platform and target framerates.

In Topic: What's the advantage of Spherical Gaussians used in The Order vs. Envirom...

17 May 2016 - 12:53 AM

"Real time"? "Infinite bounces"? "Dynamic"? I'm completely lost as to how environment maps gets you anything like that over spherical guassians/harmonics. But generally SG/H is used both for memory requirements and because it's easy to fit to arbitrary BDRFs.

In Topic: Spherical interpolation for multi transfer basis

16 May 2016 - 03:42 PM

Here's the paper from above: https://mediatech.aalto.fi/~ari/Publications/SIGGRAPH_2015_Remedy_Notes.pdf


Also has a nice hack for reducing light leak

In Topic: Irrandiance Volume v.s. 4-Basis PRT in Farcry

30 April 2016 - 09:55 PM

If you're disappointed with 2-band spherical harmonics (perfectly understandable) you can take a look at spherical guassians, or just play around with SH/SG stuff here: https://github.com/kayru/Probulator