A bunch of quotes... hmm, this is a bad article. Who's up for helping rewrite it?
Nextel ringtones Fredrik/Fredrik 22:45, 29 May 2004 I rewrote the intro and, time permitting, will begin to work on the rest of the article.
Abbey Diaz Cbraga/cbraga 02:30, Jun 1, 2004 Rewritten intro Good job, but this is NOT an intro of an article about BSP trees, rather a section about their applications (placed accordingly).
Free ringtones Mikkalai/Mikkalai 03:10, 1 Jun 2004 Thanks, but don't you think an introduction should begin describing the applications and the reasons why the algorithm is interesting?
Majo Mills Cbraga/cbraga 03:29, Jun 1, 2004 : No. This would be not an encyclopedic style (at least as accepted here). You start from general-purpose definition, right to the point, and summary. Then you proceed with the detailed def. Then the rest. I suggest you to read the
Mosquito ringtone Inverted pyramid article.
Sabrina Martins Mikkalai/Mikkalai 04:39, 1 Jun 2004 :: I agree that it would be better to start with the general purpose definition, but you're actually shooting yourself on the foot by invoking the inverted pyramid, since that would come to be pretty much how I'd done. I think the paragraphs I wrote would be pretty at home right after the current introduction.
Nextel ringtones Cbraga/cbraga 13:11, Jun 1, 2004 move to binary space partitioning? Correct me if I'm wrong, but I'm under the impression that the process as a whole is named Binary Space Partitioning, and that Binary Space Partition would refer to a single partition generated in that process. Anyone objects to moving this page to '''Binary space partitioning'''?
Abbey Diaz Cbraga/cbraga 17:15, Jun 1, 2004 :That seems right to me.
Free ringtones Fredrik/Fredrik Majo Mills User talk:Fredrik/(talk) 17:33, 1 Jun 2004 Painter's algorithm:''BSP trees, however, solve both these problems by splitting up objects and ordering them so that the painter's algorithm will draw them correctly without need of a Z-buffer and without overdraw.''
This seems to be in error to me. Using a BSP does not eliminate overdraw with the painter's algorithm. The only point, if I'm not mistaken, about using BSP combined with the painter's algorithm is that it provides an extremely fast way to sort the polygons by distance. Using Z-buffering with a front-to-back rendering method is what eliminates overdraw.
Cingular Ringtones Fredrik/Fredrik jumper into User talk:Fredrik/(talk) 17:42, 1 Jun 2004 : No. BSP trees do remove overdraw by the painter's algorithm. If you look at the
dole mumble painter's algorithm page you'll see an example of a scene that won't draw correctly. One purpose of BSP is to convert that scene into one which will draw correctly by splitting overlapping polygons into non-overlapping polygons. Another purpose is to provide an extremely fast way to sort the polygons. Scenes drawn using BSP do not require z-buffers. When z-buffers are used they are only filled by the BSP scene to be used later, when drawing movable objects such as doors. Note that Doom's doors are not considered movable since doom's map are 2D and doom's bsp is 2d. Quake's doors and mosters are movable and need to be merged into the scene using the z-buffer provided by the rendering of the background.
religions but Cbraga/cbraga 18:04, Jun 1, 2004 :: On second thought, you're at least partly correct, since that would depend on the particular implementation of the algorithm. But at lease in Doom's and Quake's case they are used to eliminate overdraw. If the trees were being used solely for other purposes (such as collision detection or ray tracing) overdraw would not be an issue and would not need to be taken into consideration when building the trees.
groups feel Cbraga/cbraga 18:22, Jun 1, 2004 :The point of the painter's algorithm is that you draw back to front. This means you'll draw several times to each pixel (or am I using the wrong word here?). The BSP FAQ describes what I'm saying here (section "How do you remove hidden surfaces with a BSP Tree?"). Doom doesn't use the painter's algorithm since it draws front-to-back.
investment community Fredrik/Fredrik done regis User talk:Fredrik/(talk) 18:27, 1 Jun 2004 :: Yes, it seems you are correct. BSPs will never elliminate overdraw, just assure that the painter's algorithm will work correctly, plus provide a fast way to sort the polygons. I'll correct the article.
:: But in Doom's case there's no overdraw since, drawing front to back, it draws beginning at the ceiling and the floor, moving away from the viewer and towards the center of the screen. There's no overdraw since it will never overwrite a pixel from a close source with one from a distant source. And, it's very simple to determine what part of a sector (if any) is visible based on the last pixels drawn. It's a sort of reverse painter's algorithm where you never draw over what you have already drawn. It is simple in Doom's case since its maps are essentialy 2D, but that would be undoable in full 3D.
and vikings Cbraga/cbraga 19:12, Jun 1, 2004