Texture mapping a cube

[az_rr]

Hi guys

I am having a few troubles trying to texture a cube. I am trying to wrap one texture around the cube but I dont understand how this can be achieved.

Attached is how it currently looks and the texture I want to wrap around the cube

  
  
ofVec3f vertices[] = {  
    ofVec3f(+h,-h,+h), ofVec3f(+h,-h,-h), ofVec3f(+h,+h,-h), ofVec3f(+h,+h,+h),  
    ofVec3f(+h,+h,+h), ofVec3f(+h,+h,-h), ofVec3f(-h,+h,-h), ofVec3f(-h,+h,+h),  
    ofVec3f(+h,+h,+h), ofVec3f(-h,+h,+h), ofVec3f(-h,-h,+h), ofVec3f(+h,-h,+h),  
    ofVec3f(-h,-h,+h), ofVec3f(-h,+h,+h), ofVec3f(-h,+h,-h), ofVec3f(-h,-h,-h),  
    ofVec3f(-h,-h,+h), ofVec3f(-h,-h,-h), ofVec3f(+h,-h,-h), ofVec3f(+h,-h,+h),  
    ofVec3f(-h,-h,-h), ofVec3f(-h,+h,-h), ofVec3f(+h,+h,-h), ofVec3f(+h,-h,-h)  
};  
vertexData.addVertices(vertices,24);  
  
static ofVec3f normals[] = {  
    ofVec3f(+1,0,0), ofVec3f(+1,0,0), ofVec3f(+1,0,0), ofVec3f(+1,0,0),  
    ofVec3f(0,+1,0), ofVec3f(0,+1,0), ofVec3f(0,+1,0), ofVec3f(0,+1,0),  
    ofVec3f(0,0,+1), ofVec3f(0,0,+1), ofVec3f(0,0,+1), ofVec3f(0,0,+1),  
    ofVec3f(-1,0,0), ofVec3f(-1,0,0), ofVec3f(-1,0,0), ofVec3f(-1,0,0),  
    ofVec3f(0,-1,0), ofVec3f(0,-1,0), ofVec3f(0,-1,0), ofVec3f(0,-1,0),  
    ofVec3f(0,0,-1), ofVec3f(0,0,-1), ofVec3f(0,0,-1), ofVec3f(0,0,-1)  
};  
vertexData.addNormals(normals,24);  
  
static ofVec2f tex[] = {  
    ofVec2f(1,0), ofVec2f(0,0), ofVec2f(0,1), ofVec2f(1,1),  
    ofVec2f(1,1), ofVec2f(1,0), ofVec2f(0,0), ofVec2f(0,1),  
    ofVec2f(0,1), ofVec2f(1,1), ofVec2f(1,0), ofVec2f(0,0),  
    ofVec2f(0,0), ofVec2f(0,1), ofVec2f(1,1), ofVec2f(1,0),  
    ofVec2f(0,0), ofVec2f(0,1), ofVec2f(1,1), ofVec2f(1,0),  
    ofVec2f(0,0), ofVec2f(0,1), ofVec2f(1,1), ofVec2f(1,0)  
};  
vertexData.addTexCoords(tex,24);  
  
static ofIndexType indices[] = {  
    0,1,2, // right top left  
    0,2,3, // right bottom right  
    4,5,6, // bottom top right  
    4,6,7, // bottom bottom left	  
    8,9,10, // back bottom right  
    8,10,11, // back top left  
    12,13,14, // left bottom right  
    12,14,15, // left top left  
    16,17,18, // ... etc  
    16,18,19,  
    20,21,22,  
    20,22,23  
};  
vertexData.addIndices(indices,36);  
vertexData.setMode(OF_PRIMITIVE_TRIANGLES);  
  
myTexture.bind();  
vertexData.drawFaces();  
myTexture.unbind();  
  

[kalwalt]

this technique is called CubeMapping , iit is used,for example, to make skybox i’ve made a little addon for this. look at: https://github.com/kalwalt/ofxSkyBox maybe this may help you in what you intend to do.

[az_rr]

Thanks kalwalt. Thats what I was looking for but I have run into another problem.

What I what to do I have a grid of cubes, 4x4, 16 cubes in total.

I have managed to create the grid but now there is a problem with the shader. I get the error

  
OF: OF_LOG_WARNING: ofShader: releasing id not found, this shouldn't be happening releasing anyway  
OF: OF_LOG_WARNING: ofShader: releasing program not found, this shouldn't be happening releasing anyway  

Here is my code. It seems as soon as I have a vector of skyboxes the shaders break

  
  
#include "ofMain.h"  
#include "ofxSkyBox.h"  
  
class CubeManager  
{  
public:  
      
    void                setup(int rows, int cols);  
    void                update();  
    void                draw();  
      
    vector<ofxSkyBox> cubes;      
    ofCamera            camera;  
     
};  
  

  
  
//--------------------------------------------------------------  
void CubeManager::setup(int rows, int cols)  
{  
    camera.setPosition(ofVec3f(280, 230, 1000));      
	camera.cacheMatrices(false);  
      
    int spacer = 20;  
              
    for(int i = 0; i < cols; i++)  
    {  
        for(int j = 0; j < rows; j++)  
        {  
            ofxSkyBox skybox;  
            skybox.setPos(j*(150+spacer), i*(150+spacer)); //I added this to ofxSkyBox to help position the boxes  
            skybox.setSize(150,150,150);//I added this to ofxSkyBox to set the size of the boxes  
            skybox.load();  
            cubes.push_back(skybox);  
        }  
    }  
}  
  
//--------------------------------------------------------------  
void CubeManager::update()  
{  
}  
  
//--------------------------------------------------------------  
void CubeManager::draw()  
{  
    camera.begin();  
    for(int i = 0; i < cubes.size(); i++)  
    {  
        ofRotate(ofGetElapsedTimef()*i, 10, 50, 20 );  
        cubes[i].draw();  
  
    }  
    camera.end();  
}  
  


[kalwalt]

Probably you have to do your class (maybe inherited from ofxSkyBox…or a new one) in which it has his method draw where you draw multiple box with only one call to the shader:

  
  
  
void ofxMyClass::draw(int numBoxes, int rows, int cols) {  
  
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);  
  
  
		glEnable(GL_TEXTURE_CUBE_MAP_ARB);  
  
		glDepthFunc(GL_LEQUAL);  
		glEnable(GL_DEPTH_TEST);  
		cubeshader.begin();  
		//glDisable(GL_DEPTH_TEST);  
		glActiveTexture(GL_TEXTURE0);  
		cubeMap.bind();  
  
  
  
		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);  
	   	glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);  
  
  
  
  
  
        cubeshader.setUniform1i("EnvMap", 0);  
    	glMatrixMode(GL_MODELVIEW);  
    	glPushMatrix();  
  
         for( int i = 0; i < numBoxes; i++){  
  
         //code to draw multiple boxes with numBoxes , rows and cols  
	  
  
         }  
  
	cubeshader.end();  
  
	glDisable(GL_TEXTURE_CUBE_MAP_ARB);  
  
	glDisable(GL_DEPTH_TEST);  
   	glPopMatrix();  
  
  
  
}  
  
  

Also i think you might use another shader instead of which inside of skybox.
Let me know if this suggestion is right or not.
regards