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gameprogrammer2005

Meshing? a fake lighting technique...

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Has anyone here heard (or understands ) the theory behind a technique called 'meshing' ?? It's basiclly a technique that was used to 'fake' real lighting used in games that use 2D pre-rendered backgrounds with animated characters. Alone In The Dark 4 used it, and i think i remember reading an article a long time ago, that the Nocturne engine..although the lighting technology was impressive at the time ...1999, it also used this 'meshing'... (Terminal Reality Inc) used it for the Blair Witch Series of games. Can anyone point me to anything (can't find anything on google) that explains a bit of theory about how it works, or if anyone here has had ' hands on' experience (maybe a dev from Terminal-Reality, that could share some knowledge) or anyone else that could explain a bit about it in detail would be even better:) While i'm here.. also, does anyone here know how the 'mirrors' were done (just an explanation or some theory on it) in these style games? as it is a pre-rendered image (not a real 3D world) how is it possible to say..reflect the player and the enviroment(which is really just a 2D image) into/onto a mirror object within a scene? (render to texture?? not sure). Any insight into any of the two above questions would be a great help. These are quite old games now(by todays and next gen standards) using fairly old tech (i.e no shaders) and i believe that the Nocturne engine used DX7 tech. Here is part of the article i read about recently about the use of 'meshing' in the Alone In The Dark 4 game... " Alone in the Dark: The New Nightmare borrows heavily from the Resident Evil series, complete with all of the trappings involved in this style of game. This game tries very hard to innovate with a lighting technology known as meshing, or in layman's terms, simulated real-time lighting. Carnby and Cedrac both come equipped with a flashlight as standard equipment, and as you make your way through the dark recesses of the mansion, you can illuminate darkened areas with your flashlight, which serves to add to the dark and gloomy feel of the game. While the visual trickery is quite a sight to see on the PlayStation, the effect soon begins to wear thin after you realize that it does not necessarily play a key role in the overall scheme of the game. Also making use of the meshing system is the lighting of prerendered backgrounds when lightning strikes. In several areas of the game, you might catch a glimpse of a dark figure standing right next to your character, only to have it disappear moments later. In all, it does make for some suspenseful gameplay, but when you get down to it, it's nothing more than eye candy." Cheers.

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swordfish    276
Not positive but I think this is what you are looking for:

http://www.google.com/search?q=simulated+real-time+lighting

Also not sure but maybe mirrors were done the same way?

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Thanks for trying to help, but i'm interested in either a solid link(if there is is one.. i can't find one on the technique 'meshing' )..this is quite different i think from other simulated lighting techinques...and yes the mirrors (iv'e actually almost (not perfect yet) come up with a way to simulate a mirror (but it only refelects the player so far..) but i'm really after some info/theory on meshing if possible ;-)

Thanks anyway.
cheers.

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Guest Anonymous Poster   
Guest Anonymous Poster
I really don't know, but one possibility is that they prerendered the scenes but kept simplified meshes in the engine for the lighting. The scene is drawn, and then the meshes are rendered, but only for lighting purposes, so maybe everything is drawn in white with an alpha value corresponding to the brightness of the light, or something like that, maybe light mapping, so the lighting brightens the prerendered scene in an appropriate looking way.

As for mirrors, if the scene is prerendered, can't the scene shown in the mirror be prerendered too? Or can the mirror be moved around?

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Cheers AP, going to try out a few ideas for lighting the backdrops today(including the ones you gave).

I have managed to find a little bit more info about how to simulate nice lighting with pre-rendered backgrounds...one bit of advice was from a post YAN L replied to here at GD.NET(so i will be reading that again!).

http://www.gamedev.net/community/forums/topic.asp?topic_id=253145&whichpage=1�

I think there are several ways to do it, problem is the little info i have read so far on it, seems to differ.

" a programming trick called "meshing, " which simulates real-time lighting on the 2D backdrops. Each of the 1200 prerendered backgrounds comes in multiple versions where different portions of the background are lit. The game sorts through the different backgrounds depending on where the player points the flashlight. It all happens so fast and smooth that the illusion of a real light being cast on the environment is produced. "

Would have been great to get a reply here from someone like Jeff Mills (but that's probably not likely LOL)...oh well.

cheers.



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I'm going to bump this up (sorry mods) for two reasons:

(a) i honestly believe there is SOMEONE that visits GD.NET that understands the theory behind the 'meshing' technique' and can help me ;-)

(b) All attempts so far, haven't worked properly..i got pretty good results with just using a 'sprite' based technique....this isn't good enough!!!

I want to know the proper way to do 'meshing'....

surely there is someone out of the ammount of people that visit here that have heard of this techinque?? its an old technique guy!!! it doesn't even use any shaders!! come on! LOL

hope someone can ' shed ' some light (no pun intended).
cheers.

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