I''ve loaded two bitmap, i want the second bitmap to be the background and i want to rotate the first bitmap. Where''s the problem??? how can i "select" which is the bitmap to manipulate at a certain point of my code?? I don''t want to rotate the second bitmap !!!!!!!!!!!!!!!!!!!!!!!!!!!! Here''s my code ("ripped" from a tutorial) procedure DrawGLScene(); begin glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT); glLoadIdentity(); glTranslatef(0.0,0.0,-5.0); //which bitmap ?????? glRotatef(xrot,1.0,0.0,0.0); //which bitmap ?????? glRotatef(yrot,0.0,1.0,0.0); //which bitmap ?????? glRotatef(zrot,0.0,0.0,1.0); //which bitmap ?????? glBindTexture(GL_TEXTURE_2D, texture[0]); //here i select the bitmap to be rotated glBegin(GL_QUADS); glNormal3f(-1.0, 0.0, 0.0); glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0, -1.0); glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0, 1.0); glTexCoord2f(1.0, 1.0); glVertex3f(-1.0, 1.0, 1.0); glTexCoord2f(0.0, 1.0); glVertex3f(-1.0, 1.0, -1.0); glEnd(); xrot := xrot + 0.5; yrot := yrot + 2.7; zrot := zrot + 0.3; glBindTexture(GL_TEXTURE_2D, texture[1]); //this is the background!!! glBegin(GL_QUADS); glNormal3f(-2.0, 0.0, 0.0); glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -2.0, -2.0); glTexCoord2f(2.0, 0.0); glVertex3f(-2.0, -2.0, 2.0); glTexCoord2f(1.0, 2.0); glVertex3f(-2.0, 2.0, 2.0); glTexCoord2f(0.0, 2.0); glVertex3f(-2.0, 2.0, -2.0); glEnd(); end; Many thanks!!!!!!!!!!!

Draw your background before you translate and rotate (after glLoadIdentity). OpenGL is a very procedural language. Everything is done immediately and forever. If you rotate, then everything that will be done afterward will be rotated.

EL

Try this! (so you use Delphi?)

procedure DrawGLScene();

begin
glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0,0.0,-5.0); //

glRotatef(xrot,1.0,0.0,0.0); //These are just
glRotatef(yrot,0.0,1.0,0.0); //for the whole
glRotatef(zrot,0.0,0.0,1.0); //rotation of the scene

glPushMatrix();

glBindTexture(GL_TEXTURE_2D, texture[0]);

glBegin(GL_QUADS);
glNormal3f(-1.0, 0.0, 0.0);
glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0, -1.0);
glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0, 1.0);
glTexCoord2f(1.0, 1.0); glVertex3f(-1.0, 1.0, 1.0);
glTexCoord2f(0.0, 1.0); glVertex3f(-1.0, 1.0, -1.0);
glEnd();

xrot := xrot + 0.5;
yrot := yrot + 2.7;
zrot := zrot + 0.3;

glPopMatrix();

glPushMatrix();

glBindTexture(GL_TEXTURE_2D, texture[1]); //this is the background!!!

glBegin(GL_QUADS);
glNormal3f(-2.0, 0.0, 0.0);
glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -2.0, -2.0);
glTexCoord2f(2.0, 0.0); glVertex3f(-2.0, -2.0, 2.0);
glTexCoord2f(1.0, 2.0); glVertex3f(-2.0, 2.0, 2.0);
glTexCoord2f(0.0, 2.0); glVertex3f(-2.0, 2.0, -2.0);
glEnd();

glPopMatrix();

end;


Everytime you use a new ''object'' You have to use the glPush..PopMatrix-thing!
So you can manipulate these objects and the others are not affected!

Hope this helps!

bye
Gunhed

Sorry made a mistake!!!

new code:

procedure DrawGLScene();

begin
glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0,0.0,-5.0); //

glRotatef(xrot,1.0,0.0,0.0); //These are just
glRotatef(yrot,0.0,1.0,0.0); //for the whole
glRotatef(zrot,0.0,0.0,1.0); //rotation of the scene

glPushMatrix();

glRotatef(xrot2,1.0,0.0,0.0); //These are just
glRotatef(yrot2,0.0,1.0,0.0); //for the whole
glRotatef(zrot2,0.0,0.0,1.0); //rotation of the scene

glBindTexture(GL_TEXTURE_2D, texture[0]);

glBegin(GL_QUADS);
glNormal3f(-1.0, 0.0, 0.0);
glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0, -1.0);
glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0, 1.0);
glTexCoord2f(1.0, 1.0); glVertex3f(-1.0, 1.0, 1.0);
glTexCoord2f(0.0, 1.0); glVertex3f(-1.0, 1.0, -1.0);
glEnd();

xrot2 := xrot2 + 0.5;
yrot2 := yrot2 + 2.7;
zrot2 := zrot2 + 0.3;

glPopMatrix();

glPushMatrix();

glBindTexture(GL_TEXTURE_2D, texture[1]); //this is the background!!!

glBegin(GL_QUADS);
glNormal3f(-2.0, 0.0, 0.0);
glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -2.0, -2.0);
glTexCoord2f(2.0, 0.0); glVertex3f(-2.0, -2.0, 2.0);
glTexCoord2f(1.0, 2.0); glVertex3f(-2.0, 2.0, 2.0);
glTexCoord2f(0.0, 2.0); glVertex3f(-2.0, 2.0, -2.0);
glEnd();

glPopMatrix();

end;

Everytime you use a new ''object'' You have to use the glPush..PopMatrix-thing!
So you can manipulate these objects and the others are not affected!

Hope this helps!

bye
Gunhed