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#ActualFrenetic Pony

Posted 30 June 2013 - 03:17 PM

For the current generation lightmaps are most definitely in, even if most have moved to spherical harmonic terms in order to get normal maps some nice directional light. Even Cryengine 3's image based lighting is very similar in result and application, though it was first used in driving games (hey, you've got a realtime updated environment map anyway.)

 

The one exception I can think of is Far Cry 3. They take a volume, apply a spherical harmonic lighting term to it, but update that term. Basically they've pre-calculated a function for light bounce for each area, encode that into a spherical harmonic probe, and use that to light. Each probe covers something like 4 meters squared of the terrain, and they load and X by X grid of probes around the player, not enough memory to extend the probes all the way to the horizon, and they update something like one probe a frame. Because the sun isn't moving too fast, it's not to noticeable to just update slowly. "Deferred radiance transfer volumes" if that's what you want to call it. http://fileadmin.cs.lth.se/cs/Education/EDAN35/lectures/L10b-Nikolay_DRTV.pdf

 

Then for the next generation. Well there's something like what Far Cry 3 does, just using more compute/memory (higher density grid? higher order spherical harmonics? etc.) Or a bunch of hack that are extremely limited and more of a neat special effect rather than actually working for lighting an entire level, a lot of attempts that produce results that aren't good enough/have too many artifacts/take up too many milliseconds/etc. And voxel cone tracing if you can actually get it working. EG

 

 

 

One of the biggest problems I can think of is, the everything is shiny problem. Specular contribution of materials is just as prevalent as diffuse, and yet so many attempts at more realtime GI out there are diffuse only. Simply because diffuse is easier because its lower frequency, EG less memory and less samples.


#2Frenetic Pony

Posted 30 June 2013 - 03:11 PM

For the current generation lightmaps are most definitely in, even if most have moved to spherical harmonic terms in order to get normal maps some nice directional light. Even Cryengine 3's image based lighting is very similar in result and application, though it was first used in driving games (hey, you've got a realtime updated environment map anyway.)

 

The one exception I can think of is Far Cry 3. They take a volume, apply a spherical harmonic lighting term to it, but update that term. Basically they've pre-calculated a function for light bounce for each area, encode that into a spherical harmonic probe, and use that to light. Each probe covers something like 4 meters squared of the terrain, and they load and X by X grid of probes around the player, not enough memory to extend the probes all the way to the horizon, and they update something like one probe a frame. Because the sun isn't moving too fast, it's not to noticeable to just update slowly. "Deferred radiance transfer volumes" if that's what you want to call it. http://fileadmin.cs.lth.se/cs/Education/EDAN35/lectures/L10b-Nikolay_DRTV.pdf

 

Then for the next generation. Well there's something like what Far Cry 3 does, just using more compute/memory (higher density grid? higher order spherical harmonics? etc.) Or a bunch of hack that are extremely limited and more of a neat special effect rather than actually working for lighting an entire level, a lot of attempts that produce results that aren't good enough/have too many artifacts/take up too many milliseconds/etc. And voxel cone tracing if you can actually get it working. EG

 

 


#1Frenetic Pony

Posted 30 June 2013 - 03:06 PM

For the current generation lightmaps are most definitely in, even if most have moved to spherical harmonic terms in order to get normal maps some nice directional light. Even Cryengine 3's image based lighting is very similar in result and application, though it was first used in driving games (hey, you've got a realtime updated environment map anyway.)

 

The one exception I can think of is Far Cry 3. They take a volume, apply a spherical harmonic lighting term to it, but update that term. Basically they've pre-calculated a function for light bounce for each area, encode that into a spherical harmonic probe, and use that to light. Each probe covers something like 4 meters squared of the terrain, and they load and X by X grid of probes around the player, not enough memory to extend the probes all the way to the horizon, and they update something like one probe a frame. Because the sun isn't moving too fast, it's not to noticeable to just update slowly. "Deferred radiance transfer volumes" if that's what you want to call it. http://fileadmin.cs.lth.se/cs/Education/EDAN35/lectures/L10b-Nikolay_DRTV.pdf

 

Then for the next generation. Well there's something like what Far Cry 3 does, just using more compute/memory (higher density grid? higher order spherical harmonics? etc.) Or a bunch of hack that are extremely limited and more of a neat special effect rather than actually working for lighting an entire level, and voxel cone tracing. EG

 

 


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