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Asuralm

Reflection Problem

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Hi all: I have a problem when I am drawing the reflections. My code is like following:
void Reflection(){
    glDisable(GL_DEPTH_TEST);
    glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
	
    glEnable(GL_STENCIL_TEST);
    glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE);
    glStencilFunc(GL_ALWAYS, 1, 0xffffffff);
	
    DrawCheckerBoard();

    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glEnable(GL_DEPTH_TEST);			
	
    glStencilFunc(GL_EQUAL, 1, 0xffffffff);  /* draw if ==1 */
    glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
    glPushMatrix();							
	glScalef(1.0f, -1.0f, 1.0f);
        DrawObject();
    glPopMatrix();
    glDisable(GL_STENCIL_TEST);	
}				
Outside this function I have enabled GL_BLEND and drawn the floor. The problem is that the object under the floor plane is always drawn as well. And I don't know how to remove it to just remain the reflection. I tried the method in NeHe's tutorial which uses glEnable(GL_CLIP_PLANE0); glClipPlane(GL_CLIP_PLANE0, eqr); glDisable(GL_CLIP_PLANE0); around the push and pop matrix. But it removed the reflection at the same time when I used it. Does anybody know where's the mistake please??? Thanks very much!!!

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When you are using the clip plane, are you sure that your plane normal is pointing to the right direction.

Is your plane in the correct space? For example in DX with shaders the clipping plane isn't in world space.

Edit: I am not familiar with the stencil mask for doing reflections, but I can imagine that there might be some issues with the z-buffer when doing it like this.

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Yeah, I am very sure the plane normal is pointing the right direction. I believe the stencil buffer works fine but I just don't know how to remove the extra object.
How can I add screen shot on the message please? So I can express my problem a bit clear.

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