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View Full Version : Reflection Maps in DX8.1


OC-NightHawk
01-17-2004, 06:23 PM
I know its possible to do bump maps in DirectX 8.1 but is it possible to use reflection maps?

OC-NightHawk
01-19-2004, 04:25 PM
Never mind I figured it out, turns out max calls it reflective maps and directx calls it environment mapping. :shrug: Now that I found it in the help files I have this covered. Speed wise though whats faster, cubic or sphere based dynamic environment mapping?

game_dev
01-21-2004, 06:26 PM
dynamic sphere mapping is quite fast, since you use only one texture to wrap around the object.
Cube mapping on the other hand requires 4-5 textures, so it technically it will decrease fps a lot.
So I would go with sphere mapping.
Although cube map is really nice, and produces results that are incredibly good.

OC-NightHawk
01-22-2004, 01:24 AM
Originally posted by game_dev
dynamic sphere mapping is quite fast, since you use only one texture to wrap around the object.
Cube mapping on the other hand requires 4-5 textures, so it technically it will decrease fps a lot.
So I would go with sphere mapping.
Although cube map is really nice, and produces results that are incredibly good.

Awsome, so the sphere mapping is a quick and dirty option. I think I'll make it a option that can be toggled between off, sphere, or cubic. That way if a machine can handle it the best can be used. Now just to be sure I have this right, the dynamic environment mapping generates the environment map automaticly to reflect the surounding objects in the environment? Very cool. :D

game_dev
01-22-2004, 02:33 AM
well, I am not familiar with Directx, but pretty sure it is the same as opengl.

Basically, env. mapping is a dynamic way of assigning UV coordinates to your model based on the view matrix. So all directx is doing is suggesting how dynamic coordinates will look like. You on the other hand use them when rendering your model.
To make true dynamic reflection you will need to take screenshot, before rendering the object, save it in memmory so it can be used as a texture, and wrap that around using coordinates given to you by directx.
Same with cube mapping, you have to render 4-5 different screens save them in memmory, and wrap around the object.

Sorry for the the way I explain stuff, english is my second language :)

hope that helps ,

me

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