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About GiXeLz

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  1. GiXeLz

    World Tech Tribune on L33t haX0r skillz

    i dunno, i managed to learn a lot about Doom's occlusion culling just by playing with it. i'm tempted to write a simple portal engine now. :)
  2. GiXeLz

    I Stole Cyb's Car, And I'm Not Sorry

    they don't appear to be used in Tenebrae? if that were true, there'd be no bump mapping in Tenebrae. and it should be able to run on gf2, considering doom3 will capable of running on a gf1 (and uses the same "hardware pixel shaders")..
  3. GiXeLz

    Question about shadows

    I don't see why not. You just set an ignore flag on the light so when it comes time to render everything, it just skips that light. Then it's simply a matter of associating a light with the object representing the light so that when you shoot and break the object, the light itself will react accordingly.
  4. GiXeLz

    interesting portal problem....

    As far as I can tell, light isn't cast from the mirror onto the scene if there is a light in the scene. But I dunno. I also don't think you will be able to have two mirrors visible to eachother eg: within eachother's line of sight. That would just lag the engine to a lockup.
  5. GiXeLz

    The 3D engines are getting more real

    First of all, Carmack toyed with radiosity in Quake2, not Quake3. He decided the hard-edged "simpler" shadows of Quake1 were better because they were cheaper to calculate and the players didn't seem to care about the radiosity in Quake2. So he ditched it with Quake3 and stuck with a simple lighting algorithm. As for radiosity in realtime, it's going to be a while before it ever comes to a reality if we follow the path we are currently on. It's hard to explain but radiosity goes alot slower than most people think. You could do a quick-hack radiosity where light can only rebound once off a surface onto another surface once but that would still be exponentially slower for each triangle you add into the scene. Radiosity is a ways off if we keep doing things the way we are now (eg: Doom3).
  6. GiXeLz

    Offtopic: Bumpmaping

    Some crazy strict regulations on this forum.
  7. GiXeLz

    Question about shadows

    Xian: Ambient light will look ok in SOME places. I don't think Carmack would say the world will be static and show us some footage (in legacy video) of a swinging light. The two best choices are radiosity lightmaps and no ambience. With ambience it just looks wrong in some cases. It won't be pitch black where it should be (which it will at times). Radiosity lightmaps just add another pass to the already-bloated rendering pipeline. So they are out of the question. Starting with zero light is the cheapest. Well, I am sure ambient light will be used in few of the maps, so don't worry about it. In all the footage/screenies I have seen so far, ambient light wouldn't fit very well. Unless it was VERY VERY VERY super low ambient. But whatever.. And yay for the technology forum! :D
  8. GiXeLz

    Offtopic: Bumpmaping

    Everything is generally going to be bump mapped. Except for 2D gfx, like text, console, etc.. I devised a GeForce3/4 pipeline where I use 3 register combiners for each pass, 2 passes per light. But I still have the depth pass and diffuse color pass to put on there. On GeForce3/4 is 2+2n passes, where 'n' is the number of lights in the scene. This also varies with stuff like alpha-masking (textures with holes, like fences, grates, etc).
  9. GiXeLz

    Question about shadows

    Doom3 calculates the shadows formed by ALL geometry PER light. Meaning if you have ten lights around a guy (very slow) then 10 shadows will be cast off of him. But the other lights may illuminate the shadows formed by other lights. Doom3 does NOT DRAW SHADOWS onto the scene. It only draws light. If light is blocked, light simply isn't drawn. The engine doesn't do some special case shadow-drawing crap like other games.
  10. GiXeLz

    Question about shadows

    (FYI: this isn't directed at anyone specifically, just the generally clueless fans that think they know what they are talking about) It won't be faster. So shutup. You guys don't understand how it works. When there is 1 light in the scene, the renderer doesn't switch over to some single-light-in-scene optimized renderer for drawing pitch-black shadows. It uses the same rendering pipeline for a scene with one light as it does for a scene with 2 lights. The engine doesn't draw the shadows, it only draws the light. If a light is blocked by something, it doesn't draw the shadow, the light just never gets to that part of the scene. Each frame, the engine runs through the lights in the scene, one light at a time. It calculates the shape of the shadows casted onto the scene and then contributes its light to the scene outside of these shadows. At the beginning of each frame before it runs through the lights in the scene, the engine starts with the scene containing no light. Just black. Each light adds its light to the scene until they are all done. If there are parts of the scene that none of the lights contributed light to, it stays black. To get rid of pitch-black shadows, they simply increase the ambient light in the map, and shadows and crannies will only be able to get so dark. This is simply done by not starting with a black scene, but a dark-gray scene, or perhaps a precalced radiosity lightmap that is very dark, but not black. All the lights add their light and there will be no black even if none of the lights light up parts of the scene, eliminating black shadows. But ambient light also looks kinda awkward because even in a room with no lights, you will still be able to see the room. Pitch-black shadows aren't faster, they just don't have any light on them so when the perpixel maths are done with all the textures and stuff it just ends up with a black pixel. It doesn't think to itself "Hey, this is a shadow, just draw black". There are three options: -Pitch black shadows for areas with no direct illumination -Ambient light, just a crappy approximation of radiosity -Radiosity lightmaps. This would only work for static lights Radiosity lightmaps are out of the question with Doom3, just because John Carmack isn't going in that direction (it would probably be the slowest choice). Ambient light is ugly. It looks ok in some scenes, but horrid in others. And you can't have like a scary room with a flickering light revealing the environment for only fractions of a second. It will flicker still, but it won't go to a pitch black scene when it flickers off. Thus ruining the effect. Pitch black shadows are just an ambient light of zero, and would probably look better in any case. I am sure Doom3 will support ambient light, but it won't look as good as you think so most Doom3 maps will just have no ambient light.
  11. GiXeLz

    Offtopic: Bumpmaping

    It was a fun mod for a while, but the quality sucks. They are still releasing patches well after the betas! It wasn't a really complex project.
  12. GiXeLz

    Question about shadows

  13. GiXeLz

    Offtopic: Bumpmaping

    Hey, they turned a simple mod as crappy as Counter-Strike into a fully fledge store-shelved product. It can't be THAT hard to get a game onto store shelves. That is, if you have the game already.
  14. GiXeLz

    Question about shadows

    Here: http://www.van-noland.com/gixelz/howitworks.psd A 2 megabyte .psd explaining how the lighting works. Each layer is one pass ahead of the layer above it. It runs progressively downward so you can just hide the layers from top to bottom to see. To make the pixel lighter would be incorrect. Radiosity would have to make the light brighter. This is one of those situations where you wonder why does it matter. Like why does it matter if the stencil shadows in Doom3 don't match truform. It would still work, but it's wrong. Your idea of just making it brighter is called ambient light. Ambient light is faking radiosity.
  15. GiXeLz

    Offtopic: Bumpmaping

    haha.. that's not what I meant. I meant make my own GAME out of my engine. Give them that. Not the engine.