Mapping several Textures on the same surface

OpenGL Development JOGL Development
#1

Hi,

I am rendering a cylinder and mapping two different textures to the top and to the bottom face.

Both the textures are loaded in the following way:

check3dFloorFile = new File(check3dFloorPath);
        
        try {
            check3dFloorTexture = TextureIO.newTexture(check3dFloorFile, true);
        } catch (IOException | GLException ex) {
            Logger.getLogger(Viewer.class.getName()).log(Level.SEVERE, null, ex);
        }
        
        check3dFloorTexture.setTexParameteri(gl, GL2.GL_TEXTURE_MIN_FILTER, 
                                                    GL2.GL_LINEAR_MIPMAP_LINEAR);
        check3dFloorTexture.setTexParameteri(gl, GL2.GL_TEXTURE_MAG_FILTER, GL2.GL_LINEAR);
                
        check3dFloorBackFile = new File(check3dFloorBackPath);
        
        try {
            check3dFloorBackTexture = TextureIO.newTexture(check3dFloorBackFile, true);
        } catch (IOException | GLException ex) {
            Logger.getLogger(Viewer.class.getName()).log(Level.SEVERE, null, ex);
        }
        
        check3dFloorBackTexture.setTexParameteri(gl, GL2.GL_TEXTURE_MIN_FILTER, 
                                                    GL2.GL_LINEAR_MIPMAP_LINEAR);
        check3dFloorBackTexture.setTexParameteri(gl, GL2.GL_TEXTURE_MAG_FILTER, GL2.GL_LINEAR);

The problem arises when I try to render to a texture (a blank one, that has nothing to do with this first two ones):

gl.glGenTextures(1, textureID, 0);
        gl.glBindTexture(GL2.GL_TEXTURE_2D, textureID[0]);
        
        gl.glTexParameteri(GL2.GL_TEXTURE_2D, GL2.GL_TEXTURE_WRAP_S, GL2.GL_REPEAT);
        gl.glTexParameteri(GL2.GL_TEXTURE_2D, GL2.GL_TEXTURE_WRAP_T, GL2.GL_REPEAT);
        gl.glTexParameteri(GL2.GL_TEXTURE_2D, GL2.GL_TEXTURE_MIN_FILTER, GL2.GL_NEAREST);
        gl.glTexParameteri(GL2.GL_TEXTURE_2D, GL2.GL_TEXTURE_MAG_FILTER, GL2.GL_NEAREST);
        
        // null means reserve texture memory, but texels are undefined
        gl.glTexImage2D(GL2.GL_TEXTURE_2D, 0, GL2.GL_RGB, floorWidth, floorHeight,
                                                    0, GL2.GL_RGB, GL2.GL_FLOAT, null);
        
        gl.glGenFramebuffers(1, frameBufferID, 0);
        gl.glBindFramebuffer(GL2.GL_FRAMEBUFFER, frameBufferID[0]);
        
        //Attach 2D texture to this FBO
        gl.glFramebufferTexture2D(GL2.GL_FRAMEBUFFER, GL2.GL_COLOR_ATTACHMENT0, 
                                        GL2.GL_TEXTURE_2D, textureID[0], 0);
        
        // depth buffer
        //int[] depthRenderBufferID = new int[1];
        gl.glGenRenderbuffers(1, depthRenderBufferID, 0);
        gl.glBindRenderbuffer(GL2.GL_RENDERBUFFER, depthRenderBufferID[0]);
        gl.glRenderbufferStorage(GL2.GL_RENDERBUFFER, GL2.GL_DEPTH_COMPONENT, 
                                                floorWidth, floorHeight);
        gl.glFramebufferRenderbuffer(GL2.GL_FRAMEBUFFER, GL2.GL_DEPTH_ATTACHMENT,
                                            GL2.GL_RENDERBUFFER, depthRenderBufferID[0]);
        
        if(gl.glCheckFramebufferStatus(GL2.GL_FRAMEBUFFER) == GL2.GL_FRAMEBUFFER_COMPLETE)
            System.out.println("[Viewer] GL_FRAMEBUFFER_COMPLETE!!");
        else
            System.out.println("..cazzo ^^");

As soon as this code is executed, the texture mapped on the top of the cylinder disappears and all the top turns to black…

Why?

Ps: my task is to map this third rendered texture on the top of the cylinder, over the already existing one…

#2

Why not simply using multitexturing?

You should rather post your questions on the official JogAmp forum too if you want more replies and I cannot come here by using a machine with a restricted web access, you see what I mean :wink:

#3

Just use multi-texturing. IMO it’s easier to do it in a shader than by messing around with texture parameters.

#4

I guess shader means OpenGL 3 or above… Im using 2.0

#5

You can use shaders in OpenGL 2.0 too.

#6

Do you have a link to any good guide/howto/tutorial?

#7

Shaders were promoted to core in OpenGL 2.0… >_>

#8

Hey comon, im a nub :smiley:

Otherwise I would not be here asking for your help :wink:

#9

Well, sorry… :wink:

OpenGL 2 = DirectX 9 hardware (2002)
OpenGL 3 = DirectX 10 hardware (2007)
OpenGL 4 = DirectX 11 hardware (2009)

On top of this we have extensions, so some cards may for example not support OpenGL 2 fully but still support shaders, and some OGL 2 cards may support Frame Buffer Objects even though it was only promoted to core in OGL 3.

#10

Btw, it is possible to do it without shaders?

#11

Yes, but it’s messy as hell. You’ll have to Google it, since I took a look at it once, threw up and went over to using shaders.