Interesting cube mapping problem

[robert]

Hi all, I am trying out some dynamic cube mapping and I've come to a complete halt.

I don't know how to descirbe it really, and I don't have a webby site to put a screenshot on, but I'll try..

If i look straight on to the sphere that is mapped, I can make out all the faces (xpos,zneg etc) and It looks like it is using the same texture for them all (so It kinda looks like a soccer ball with the indents). But when I move around it the image will change - So at any one time it is reflecting the right image, but none of the other faces are right.

Gah, just gone and confused myself there, I may have to find somewhere to put a screenshot :P.

glViewport(0,0,texDepth,texDepth);
 
	glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
 
	GLint base = GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB;
 
	// Now set up a new perspective
	// the fov must be 90
	float fieldofview, nearclip, farclip;
	getAspectRatio(fieldofview,nearclip,farclip);
 
	gluPerspective(90, 1.0, nearclip, farclip);
 
	glMatrixMode(GL_MODELVIEW);
 
	for (int i = 0; i < 6; ++i)
	{
		//Clear the depth buffer.
		glClear(GL_DEPTH_BUFFER_BIT);
 
		//Reset modelview matrix.
		glLoadIdentity();
 
		glTranslatef(pos.x,pos.y,pos.z);
 
	//Rotate 
	glRotatef(CubeRots[i][0], CubeRots[i][1], CubeRots[i][2], CubeRots[i][3]);
 
 
		// Now render everything
		(world)->Update();
 
		glDisable(GL_TEXTURE_2D);
		glEnable(GL_TEXTURE_CUBE_MAP_ARB);
		glBindTexture(GL_TEXTURE_CUBE_MAP_ARB, cubemap);
 
 
				glCopyTexImage2D(base + i, 0, GL_RGB8, 0, 0, texDepth, texDepth,0);
		glDisable(GL_TEXTURE_CUBE_MAP_ARB);
 
 
	}
 
 
 
	// Reset THe window
	setViewportPersp();

Here are my texgens:

	glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
	glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);
 
	glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 
	glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);
	glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);
	glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);

I know it sounds confusing, but I was just wondering if anyone has had any odd occurances with CM and how they managed to fix it.

[This message has been edited by robert (edited 01-13-2003).]

[davepermen]

you can always upload on http://davepermen.net just click on free, and upload there, then copy the link(s) in here..

didn't read the post yet, just seen you need webspace

[NitroGL]

Originally posted by davepermen:
you can always upload on http://davepermen.net just click on free, and upload there, then copy the link(s) in here..

didn't read the post yet, just seen you need webspace

Heh...
You know what? I always figured you as mid 30's, and an American living in California...

[jwatte]

I always figured you as mid 30's, and an American living in California...

No; I've got a lock on that market :-)

[davepermen]

hehe.. i'm currently watching futurama, and its 00:20.. and that at the parents home, where i still do live...

not really what you expected, right?

anyways, lets try to help the original topic

one day, you know.. one day i get photos..

[rgpc]

What you've got looks OK.

Are you sure your values in "CubeRots" are correct?

Perhaps the problem is not that it's reflecting the same side of the cube but that your textures are not oriented correctly? ie. Your +Z side is joined to your X sides on the -Z side of those faces...

Try swapping your "+Z" and "-Z" to see if it makes a difference.

I know I had a heap of trouble aligning the faces on my cubemaps (only to throw away the idea of dynamic cube maps because render-to-texture is toooooooo slooooooooow!

[robert]

Hey, thanks for the site

I have uploaded the two pictures as: www.itstudents.ch/users/dave/free/files/screenshot4.jpg
and www.itstudents.ch/users/dave/free/files/screenshot5.jpg

It appears that the cube map is reflecting what the camera sees - fine, I could fix that but I don't understand why it is warping like that...

[This message has been edited by robert (edited 01-13-2003).]

[robert]

rgpc, I have tried that, but I might have missed something so I'll try again thanks.

btw, davepermen nice site! Looks very professional.

[rgpc]

Looking at your screen shots it is definitely reflecting the same image multiple times...

Just wondering, how do you draw your skybox? Presumably this is done using the "(world)->Update();" call.

Can you show us the code that does this?

It looks like the skybox is not rotated by the rotations in "CubeRots". (So naturally you would get the same image rendered 6 times)

[knackered]

I really like the idea of people being able to drop stuff onto your site like that, davep. Nice browser thing too. An improvement would be to enable people to attach a comment/link to each item they drop there.