Vbo meshes and array of multiple images

Hi oF community! This may be a rather stupid question but I’m having some trouble with a project I am doing. Just a quick overview, I am attempting to create an interactive piece where a vboMesh cycles through an array of images based on a blob tracker. Essentially the effect that I want to create is when someone steps on location A, a mesh will appear. When he/she steps on location B, another image will appear. The reason why I am using a mesh is because i want to apply shaders afterwards to play around with how the image looks.

I am currently at the stage where I am simply trying to apply multiple images to the vboMesh. I am able to link one image to the mesh. However when I try linking the array to the mesh, i get an error saying "img declared as array of references of type ‘ofImage & (aka ofImage &’)

I am basing my code off of the vbo example hence that is why my code is like that right now. I may possibly be approaching this problem in an incorrect way, but any help will be much appreciated right now!

without digging into your logic / what you are trying to do – if you want to pass the array by reference (which you should), you need to declare it properly:

(from http://stackoverflow.com/questions/7902433/passing-array-arguments-by-reference)

char  & x[5] // declare x as array 5 of reference to char (not valid C++!)
char (&x)[5] // declare x as reference to array 5 of char

in this case, i think the compile interprets this as an array of ofImage references, vs. a reference to an ofImage array…

It does not seem that you are using an array within the function, just its MAXIMAGES’th element. If that’s the intent, just pass that single element of array as ofImage& img and then within the function use img variable instead of img[MAXIMAGES].


thanks for the help @zach and @eight! I realized that I’m actually not familiar enough with pointers and reference to be diving into that area. I took the & out and changed a couple parameters. Instead of having:

ofVec3f getVertexForming(ofImage& img, int x, int y);

i changed it to:

ofVec3f getVertexForming(int x, int y);

It somehow struck me that I didn’t need to use an image to create the points on which the mesh will be based on. With this in mind, i changed that section of the code to: (IMAGESIZE is simply 1000 ~ all my images are 1000x1000, MAXIMAGES is still set to 5)

ofVec3f ofApp::getVertexForming(int x, int y) {
ofColor color = img[MAXIMAGES].getColor(x, y);
if(color.a > 0) {
    float z = ofMap(color.a, 0, 255, -480, 480);
    return ofVec3f(x - IMAGESIZE / 2, y - IMAGESIZE / 2, z);
}else {
    return ofVec3f(0, 0, 0);

the issue that I am running into now is cycling through the array. I currently have


what happens from this is that my mesh cycles through the entire array on it’s own. Any thoughts on how I can change the image on my mesh one by one on click? I know that ofMesh has a mesh.update() function but vboMesh does not seem to have any.
Thank you very much for being so patient with me. I’m relatively new to C++ and still trying to learn as I go.