I tried the Demo game... Alone in The Dark : A New Nighrmare. It uses OpenGL, the character has a nice Flashlight, I turn it on and it luminates the wall. (--basic story, right ?--) except that the background is 2D !! (that includes the wall). I would really REALLY want to know how to do this, Luminating a 2D Object with a 3D effect Flashlight (as if in the game).

well i havent played the pc version only the playstation one. [good game ]

what they did was render multiple backgrounds and overlayed them.

for example, your in a room. well the background was rendered once for the dark night feel.. and then they rendered the exact same sceen fully lit.

in the game when you turn on the flashlight they track where its hitting and they overlay a section in the shape of the flashlight''s light of the lit rendered background over the dark one.

i hope this helps, im not the best at getting my ideas/thoughts in words..

-latez

They really do it that way? I really thought that they''d put an external light source right in front of the screen (a la, z = 0.1f) and then it''d illuminate whatever in front of it. Of course, you''d need vectored lighting (I think that exists, don''t quote me), but that''s my big guess...

~ Dragonus

Hmm... Just checked the PSX Version...

Nice... Invicible Polygons for Colision Detection. For luminated objects they redraw some polygons above the backgrounds to luminate it (in full 3D i guess). And it looks like vertex lighting for sure...

This is the first time I see a game with prerendered backgrounds but all objects (sprites) has it''s own polygon, almost like the game is full 3D !!

(In case you want to know How I found it...
I Checked using an Emu that is capable for showing wireframe and disabling Alpha blending)

Yeah vectered lighting exsits and is easy to use in openGL. I think if the w component of the lights position is zero the light is treated as a directional source(Vector emanating from some arbitary point, representing a direction in space) But if w is the value 1 then the light is positioned at some point in the coordinate system.


~Steve~

Edited by - steveharper101 on August 28, 2001 3:14:46 PM