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pat777
05-31-04, 10:51 PM
It looks like a very neat effect. nVIDIA's Last Chance Gas demo, although running very slow looks extremely impressive. If we see this type of effect in future GPUs at a playable in-game frame-rate I think graphics will look much better. I heard radiosity is a way to achieve global illumination.

Greg
05-31-04, 11:11 PM
Global Illumination simply means to account for all the different types of illumination present in a view of a scene. These things include direct, indirect and specular reflections, as well as transport through participating media (see through objects like wax or fog).

Actually computing a reasonable global illumination solution in reasonable time is a big issue in graphics today, from trying to improve real-time games, to making special effects in movies more realistic. Many methods exist to compute specific parts of the global illumination solution. Ray tracing, Radiosity, Photon mapping, spherical harmonics are all names you would have heard of and all perform part, or an approximation of part of the solution. The best results currently come from mixing these such as 'ray tracing plus radiosity' or 'ray tracing with an irradiance map'.

There is info on how the Gas Station Demo was made at nVidias web site.

Hopefully I will edit this post with an example of some global illumination in action.
Edit: Was unable to obtain permission to post development images.

Nv40
06-01-04, 01:12 AM
Global illumination is at the moment the most requested feature for Realistic photoquality graphics.. is more advanced that raytracing technique (which can also produce high quality graphics too),for simulating real lights behaviour. (is like an extension of raytracing). Raytracing is accurate for real reflections ,or any -first- contact of the lighting with surfaces. but ignores that lights onces it hit a surface it keep traveling ,bouncing in many directions..everywhere ,until all its energy dissipates .so it not effective for second contact effects like -indirect illumination ,Caustics of glass .or any defraction or the scattering of the light . There is another technique that is used together with GI.. photon mapping that add more realism (or perhaps can be used for unrealism too . not real ,but looks cool and more interesting at times ) by making possible every object or surface to act as a source of light. to simulate the real life effect where objects are illuminated by light and this same object helps in the illumination of other objects or surfaces around it..

Radiosity is the name for the GLobal Illumination techniques of others SOftwares aplications. but for simplicity all advanced techniques are called Global illumination and all are extensions of raytracing. here is a very usefull read for you.. about this

http://www.3dgate.com/techniques/000424/0424rendering1.html

GI its very complex lighting technique ,and can be very very very very slow ,sometimes high quality still shot can take 40 hours!! just for 1 frame in any p4 machine.so i dont think we will see GI in games for a very long time.. but many time the results can be so close to the real life that you will have a hard time believing is not real . :D

http://www.nvnews.net/vbulletin/attachment.php?attachmentid=6145&stc=1

once you have GI lighting there is virtually no limits for the quality you can get in graphics. until today games depends of scanline rendering ,which is described above .the jump to -realtime - Global Illumination in games ,is the final frontier in gaming graphics. and the diferences in the change can be as Big as the move from 2d graphics to 3d. :)

pat777
06-01-04, 02:04 AM
http://www.3dgate.com/techniques/000424/0424rendering1.html

GI its very complex lighting technique ,and can be very very very very slow ,sometimes high quality still shot can take 40 hours!! just for 1 frame in any p4 machine.so i dont think we will see GI in games for a very long time.. but many time the results can be so close to the real life that you will have a hard time believing is not real .
I wonder how complex a game with GI and volume graphics throughout the entire game will be.

Nv40
06-01-04, 02:19 AM
I wonder how complex a game with GI and volume graphics throughout the entire game will be.

the complexity is not the problem , Nvidia even have demos that simulate in very limited scenarios GI lighting in the NV30. and there are many students of Universities doing GI lighting in video cards for their post graduate studies in computer graphics. the problem is the performance of today hardware is not there today and maybe not for next 10 years for be used effectively in games . the good news is that Dx9 can simulate realism too.. albeit using much less accurate rendering techniques and workarounds.

pat777
06-01-04, 03:03 AM
the complexity is not the problem , Nvidia even have demos that simulate in very limited scenarios GI lighting in the NV30. and there are many students of Universities doing GI lighting in video cards for their post graduate studies in computer graphics. the problem is the performance of today hardware is not there today and maybe not for next 10 years for be used effectively in games . the good news is that Dx9 can simulate realism too.. albeit using much less accurate rendering techniques and workarounds.
Does GI help in shadowing? BTW, isn't complexity what causes the performance issues on these video cards?

Nv40
06-01-04, 03:58 AM
Does GI help in shadowing?

of course.. :)
Lighting will not be complete without the shadows. with GI or raytracing you can get perfect shadows.. notice the screenshot posted above ,realistic shadows everywhere. they are very soft or hard edge in real life.. it depends of the intensity of the light and the situation. and yes the complexity and the accuracy of GI is what cause it to be prohibited (performance wise) in games.

accurate Lighting makes all the diference in IQ.
take a look at the gallery of a GI renderer.

http://www.vrayrender.com/gallery/

nothing there is real . just 3d graphics with GI renderings.

pat777
06-01-04, 05:34 AM
of course.. :)
Lighting will not be complete without the shadows. with GI or raytracing you can get perfect shadows.. notice the screenshot posted above ,realistic shadows everywhere. they are very soft or hard edge in real life.. it depends of the intensity of the light and the situation. and yes the complexity and the accuracy of GI is what cause it to be prohibited (performance wise) in games.

accurate Lighting makes all the diference in IQ.
take a look at the gallery of a GI renderer.

http://www.vrayrender.com/gallery/

nothing there is real . just 3d graphics with GI renderings.
Something I noticed about shadows is that when there's multiple light sources multiple shadows from one object appear. The closer the object get's to the object it's shadowing the more the shadows combine. Does GI do this? I've only seen one shadow per object from games.
I think what really makes old games look bad is having no lightning. I think lightning is the biggest difference too.

nutball
06-01-04, 06:50 AM
http://www.vrayrender.com/gallery/

nothing there is real . just 3d graphics with GI renderings.

No ****! Really? None of those images are photorealistic IMO. Impressive, yes. Photorealistic, no. Keep trying guys, you're a few decades away yet but you'll get there!

pat777
06-02-04, 04:08 AM
I found this on google.
http://www.3d-worxx.com/behind_the_scenes/reviews/realsoft/realsoft.html

Impressive.

pat777
06-04-04, 07:37 AM
No ****! Really? None of those images are photorealistic IMO. Impressive, yes. Photorealistic, no. Keep trying guys, you're a few decades away yet but you'll get there!

If you ask me the main thing they need to improve is geometry detail.

Drumphil
06-04-04, 07:46 AM
hehe, I still remember waiting for povray to render a scene on my 386sx-16. Put it on and come back next week... Next month maybee depending on how complex the scene was. :zzzz:

Jarred
06-04-04, 01:15 PM
Nv40 pretty much covered it, but, I wanna stress that the render times are dependent on the software, and some are WAY slower than others.

GI is getting faster and faster, if you wanna see some realtime videos on how GI works within Fprime (fastest render in the world) check out the links here

http://www.worley.com/fprime.html

scroll down to about the middle where you see the picture of the scull, downlaod the video below that, where you can see "Monte Carlo" raidosity in almost realtime.

so, it won't be long befre we start seeing this in games, I'm willing to bet within the next ten years. They already got some simplified versions of it going with something called spherical harmonics.

http://www.paulsprojects.net/opengl/sh/sh.html

Jarred
06-04-04, 01:27 PM
No ****! Really? None of those images are photorealistic IMO. Impressive, yes. Photorealistic, no. Keep trying guys, you're a few decades away yet but you'll get there!

LOL, I'd be more than willing to bet if some of those were shown to an average "joe" they wouldn't know the difference.

It's already here IMO, you've seen CG in commercials, and I bet you didn't even know it. :P

Nv40
06-04-04, 10:21 PM
found another.. it looks realistic enough for me.. :)

http://www.nvnews.net/vbulletin/attachment.php?attachmentid=6216&stc=1

Jarred
06-04-04, 11:14 PM
found another.. it looks realistic enough for me.. :)



that looks really good, and to the untrained eye, you couldn't tell...

I on the other hand... can spot cg images more easily because I stare at them all day:)

Waffles
06-04-04, 11:14 PM
whoa...thats not real? DAYAMN. Who has the time to make models with that many polys in one scene.

Jarred
06-04-04, 11:26 PM
whoa...thats not real? DAYAMN. Who has the time to make models with that many polys in one scene.

I do :) It's gotten faster over the years. :P

pat777
06-05-04, 03:38 AM
that looks really good, and to the untrained eye, you couldn't tell...

I on the other hand... can spot cg images more easily because I stare at them all day:)
I could only tell from the tires and wheels and the license plate.

Jarred
06-05-04, 04:38 AM
I could only tell from the tires and wheels and the license plate.

being able to see this stuff is not always a good thing... :) , I wish I couldn't see it as easily, becasue, when I go to movies sometimes it ruins it for me, I spend time looking at flaws in the CG when I should just be enjoying the movie...

I noticed the plates and the tires as well... seem to have some weird amount of ambient light going on with the tires maybe...

there should also be a slight DOF going on too, ...all of the car is perfectly in focus, least it looks that way.

Also... theres a grain of some sort that really shows up on the white areas, ...might be some rendering artifacts.

pat777
06-05-04, 11:59 PM
http://www.vrayrender.com/gallery/image/75/

OMG, can you say photorealistic?

MUYA
06-06-04, 01:11 AM
can u say drool? lol

Jarred
06-06-04, 01:25 AM
bah... pencils and a flat table, easy cake... but it does look real :)

thing about Raidosity is... it's not to hard to get it going, makes anyone look like they can light a scene....

just finished this one up...

MUYA
06-06-04, 01:28 AM
Top stuff Jarred. I saw all your stuff at your website...kick ass man. :D

Jarred
06-06-04, 01:39 AM
Top stuff Jarred. I saw all your stuff at your website...kick ass man. :D

thanx dude I got 1 more rendering right now....