Not logged in, Join Here! or Log In Below:  
 
News Articles Search    
 

 Home / 3D Theory & Graphics / Managed Direct3D texture positioning Account Manager
 
Archive Notice: This thread is old and no longer active. It is here for reference purposes. This thread was created on an older version of the flipcode forums, before the site closed in 2005. Please keep that in mind as you view this thread, as many of the topics and opinions may be outdated.
 
mejje

May 12, 2005, 07:47 AM

Hi,

I've just started tinkering with Managed Direct3D, and have a noob question. I have a sphere with a 2:1 8192x4096 texture, Looks quite Ok, but my gfx card is downsampling it to it's max texture size (8192x4096). Is it possible to use two separate textures (4096x4096) to texture a hemisphere at a time of the same mesh?

I've tried scaling the texture with device.TextureState etc but it always cover the entire mesh. Is it impossible to place two textures at opposite ends of the same mesh?


Thanks for helping!

mejje

 
juhnu

May 12, 2005, 08:14 AM

1. split your mesh
or
2. pack your textures into a one bigger texture and change texture coordinates accordingly

AND

I don't really think you need such a big texture





juhani

 
mejje

May 12, 2005, 08:39 AM

Hi,

thanks for your comments. I guess I'll have to split the mesh then. I have investigated other methods of having a large texture on the sphere, but haven't found anything useful. What I really would like to do is to use an even bigger texture, and load appropiate elements dynamically, but I guess that means building the sphere mesh dynamically as well. Too much work ;).


Thanks again,

mejje

 
Chris

May 12, 2005, 11:05 AM

Many cards can do 2048x2048 only, and you'll still find some which are limited to 512x512. If you want to support them, you'll need a more dynamic approach anyway.

 
Jason Zelsnack

May 12, 2005, 01:32 PM

You could try using a spherified subdivided cube. If you have something like MAX or Maya create a subdivided cube and apply a spherify modifier. That pushes the cube's vertices into the shape of a sphere. You should apply your texture coordinates and textures to the faces of the cube before it is spherified. Since I'm sure you have a texture meant to be projected spherically so you will need to warp the textures for the cube. You can either write a little program for that or you can apply spherical texture coordinates to the spherified cube, then remove the spherify modifier and unfold the cube. If you render off a view of that you get your 6 square textures. If you wanted you could further subdivide each texture and achieve near infinite resolution. The downside to this technique is that texels are warped near the cube edges, but not too much and they do align to neighboring textures across borders. The best thing is that there isn't an annoying pinch at the top or bottom of the sphere.

 
mejje

May 12, 2005, 02:18 PM

Hi, thanks for an interesting idea!

The texture looks like this: http://visibleearth.nasa.gov/cgi-bin/viewrecord?11656, I'm not sure what technique I can use to modify it to fit :-/

 
This thread contains 6 messages.
 
 
Hosting by Solid Eight Studios, maker of PhotoTangler Collage Maker.