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03-09-2003, 11:39 AM
Hi.

I'm trying to use multitexturing - and it works http://www.opengl.org/discussion_boards/ubb/smile.gif

But when using 2 textures for a polygon - texture 1 as the real texture and texture 2 as lightmap - then the lightmap only darkens the real texture. Or in more clear terms:

If the lightmap is 100% white then it does NOT effect the texture
If it is 50% white (R:127,G:127:B127) then it darkens the texture a lot.

I want this to happend instead:

If the lightmap is 100% white then it brightens the texture.
If it is 50% white (R:127,G:127:B127) then it does NOT effect the texture.
If it is less than 50% white then it darkens the texture.

Is that possible? Thanks a lot in advance!
Here is the code i'm using:

glActiveTextureARB(GL_TEXTURE0_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, checker2);

glActiveTextureARB(GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, bg1);

glBegin(GL_QUADS);

glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0, 1.0);
glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 1.0);
glVertex3f(-1, 1, 0);

glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0, 0.0);
glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 0.0);
glVertex3f(-1, -1, 0);
etc...

DFrey
03-09-2003, 06:31 PM
Use a signed add blend mode, instead of a modulation blend. Though the results may look a bit washed out.

[This message has been edited by DFrey (edited 03-09-2003).]