Luminance Texture Compression Problem

OpenGL OpenGL: Advanced Coding
1

Hi everyone, May I ask a quesiton ?
I want to compress luminance 3D texture data.
But failed to compression luminance texture.

I success RGB or RGBA format texture compression with GL_COMPRESSED_RGB(A)_ARB or GL_COMPRESSED_RGB(A)_S3TC_DXT5_EXT.

Please teach me How to compress luminance texture.
( Chip = GeForce3 Ti200 , SDK = NVSDK5.1 )

glTexImage3DEXT(GL_TEXTURE_3D_EXT,0, GL_COMPRESSED_LUMINANCE_ARB,w,h,d,0, GL_LUMINANCE,GL_UNSIGNED_BYTE,ubyte_luminance);
glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS_ARB, &num_compressed_format);
compressed_format=(int*)malloc(num_compressed_format*sizeof(int));
glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS_ARB, compressed_format);
glGetTexLevelParameteriv(GL_TEXTURE_3D_EXT, 0,GL_TEXTURE_COMPRESSED_ARB,&compressed);
if(compressed==GL_FALSE){
printf(“compression failed”);
}
…

Value “compressed” is GL_FALSE and Can’t create compressed luminance texture.

2

You don’t get a compressed texture because there are no format, that the GeForce support, that compresses luminance textures.

3

Originally posted by Bob:
You don’t get a compressed texture because there are no format, that the GeForce support, that compresses luminance textures.

Thanks for reply.
However, My English is poor , so I can’t understand from your reply which
1:Can create it with some methods , but my coding is incorrect.
or
2:Never create with any coding on GeForce3.

4

ysatou,

AFAIK s3tc (which is the base for vtc) supports only RGB/RGBA textures. Or in other words: “Never create with any coding on GeForce3”

[This message has been edited by h2 (edited 02-19-2002).]

5

Thanks for explanation.