Jon
20-05-2007 18:08:33
Part I of many, I'm sure.
Some things are curiosities, some are problems. If you know more about the following, by all means chime in please.
* ever wonder why page assets are stored on disk with coords Z,X?
(ex: heightmap s4.1.4.png refers to page X=4, Z=1)
* I wonder why when I start the demo application with the camera pointed towards the ground, pages are loaded and then _unloaded_, and then _loaded_ again. Without the camera moving... Hmmm.
* I wonder why pages are hidden (easy enough to look into, think I've reached my curiosity threshold on this).
For example, last night I ran across a case where the page the camera was on was hidden. Hmmm.
* LOD stitching still annoys me, as much as I try to ignore it. But here is an interesting case: I was in an area of the map with several pages that were perfectly level (all height 0 I think). This is a good area to look at texture blending across pages, with no funny lighting issues. Anyhow, I move the camera towards a page boundary and when I hit the magic stitching distance triangles are added with Y coords above both pages. These little hills pop up. I think this is the same thing I was grumbling about last year, but having this happen on a perfectly flat region gives insight into the problem. Hmmm.
* I wonder why a shader's texture lookup at one edge of a texture returns values not even close to what is in the image. With floating point coords, the texture size isn't important (0.99 is 0.99 in any sized texture). I've dumped the texture out of PIX and examined both it and the source texture in Photoshop. It acts like there is an interpolation between the sample point and 0. The closer one gets to the edge, the smaller the sampled value. There is probably some wierd addressing mode going on. Hmmm.
Some things are curiosities, some are problems. If you know more about the following, by all means chime in please.
* ever wonder why page assets are stored on disk with coords Z,X?
(ex: heightmap s4.1.4.png refers to page X=4, Z=1)
* I wonder why when I start the demo application with the camera pointed towards the ground, pages are loaded and then _unloaded_, and then _loaded_ again. Without the camera moving... Hmmm.
* I wonder why pages are hidden (easy enough to look into, think I've reached my curiosity threshold on this).
For example, last night I ran across a case where the page the camera was on was hidden. Hmmm.
* LOD stitching still annoys me, as much as I try to ignore it. But here is an interesting case: I was in an area of the map with several pages that were perfectly level (all height 0 I think). This is a good area to look at texture blending across pages, with no funny lighting issues. Anyhow, I move the camera towards a page boundary and when I hit the magic stitching distance triangles are added with Y coords above both pages. These little hills pop up. I think this is the same thing I was grumbling about last year, but having this happen on a perfectly flat region gives insight into the problem. Hmmm.
* I wonder why a shader's texture lookup at one edge of a texture returns values not even close to what is in the image. With floating point coords, the texture size isn't important (0.99 is 0.99 in any sized texture). I've dumped the texture out of PIX and examined both it and the source texture in Photoshop. It acts like there is an interpolation between the sample point and 0. The closer one gets to the edge, the smaller the sampled value. There is probably some wierd addressing mode going on. Hmmm.