Using an Fbo texture on a GL_QUAD [SOLVED]

beginners
#1

Hi I’ve been trying to map an Fbo texture onto a quad.
So far I just get a blank screen.

Here’s what I’m currently dong:

  
         
fbo.getTextureReference().bind();  
        glBegin(GL_QUADS);  
        glNormal3f(0.0f,0.0f,1.0f);  
            glTexCoord2f(0, 0);  
            glVertex3f(sliceCoordinates[0].x, sliceCoordinates[0].y, sliceCoordinates[0].z);  
  
            glTexCoord2f(fbo.getWidth(), 0);  
            glVertex3f(sliceCoordinates[1].x, sliceCoordinates[1].y, sliceCoordinates[1].z );  
  
            glTexCoord2f(fbo.getWidth(), fbo.getHeight());  
            glVertex3f(sliceCoordinates[2].x,sliceCoordinates[2].y, sliceCoordinates[2].z );  
  
            glTexCoord2f(0, fbo.getHeight());  
            glVertex3f(sliceCoordinates[3].x, sliceCoordinates[3].y, sliceCoordinates[3].z );  
        glEnd();  
        fbo.getTextureReference().unbind();

I’m not sure what I’m doing wrong :s

#2

Looks about right. Are you drawing the fbo?

#3

I solved my problem; I calling cam.begin() before drawing to the fbo. Turns out this messes things up. It should only be called after the fbo is drawn and you start mapping the fbo texture :slight_smile:

Here’s the code in case anyone runs into a similar problem:

  
  
        //Draw simple shapes on the fbo  
        fbo.begin();  
        ofSetColor(200,200,200, 255);  
        float rectSize = volWidth * 0.3;  
        ofNoFill();  
        ofRect((volWidth / 2) - rectSize / 2, (volHeight / 2) - rectSize /2, rectSize, rectSize);  
        rectSize =  volWidth * 0.9;  
        ofRect((volWidth / 2) - rectSize / 2, (volHeight / 2) - rectSize /2, rectSize, rectSize);  
        fbo.end();  
        //begin the cam now  
        cam->begin(ofRectangle(0,0, ofGetWidth(), ofGetHeight()));  
        //Bnd the fbo texutre reference  
        fbo.getTextureReference().bind();  
        glBegin(GL_QUADS);  
        glNormal3f(0.0f,0.0f,1.0f);  
            glTexCoord2f(0, 0);  
            glVertex3f(sliceCoordinates[0].x, sliceCoordinates[0].y, sliceCoordinates[0].z);  
  
            glTexCoord2f(fbo.getWidth(), 0);  
            glVertex3f(sliceCoordinates[1].x, sliceCoordinates[1].y, sliceCoordinates[1].z );  
  
            glTexCoord2f(fbo.getWidth(), fbo.getHeight());  
            glVertex3f(sliceCoordinates[2].x,sliceCoordinates[2].y, sliceCoordinates[2].z );  
  
            glTexCoord2f(0, fbo.getHeight());  
            glVertex3f(sliceCoordinates[3].x, sliceCoordinates[3].y, sliceCoordinates[3].z );  
        glEnd();  
        //Unbind the texture and end the cam  
        getTextureReference().unbind();  
        cam->end();