   Move both camera and object
  Hello,I am trying to move an object with the mouse but it is a special situation. I want to move the object around but, for instance, when I move up I don't want to see the object from underneath it, I want to have the same view on my object. So the way I thought it, i should also move the camera, translate it to a new position. But if I translate the "eye" and the "look at" vectors of the view matrix using the same vector as for the object, the object won't move. I have been thinking about it and I didn't come up with a good solution.Does anybody have some idea about something like this and can give me some explanation about it? Thank you,Madalina   
  Compute the shift vector in global space. Translate the object, camera, and look-at positions by that vector (assuming that all those positions are global). Of course, it looks like that the object doesn't move as long as the only reference (i.e. the camera) is moved the same amount. However, as soon as the world around (that isn't moved by the shift vector, too) is seen, you have a visual reference that shows you that the object of interest is actually moved.However, it may be that the OP's wording is misunderstood. What exactly should "I don't want to see the object from underneath it" be realised? I mean, when you orbit the object around the camera you will ever see the same side of it, too.   ;  I think I didn't explain well. I don't want to orbit the object around the camera, I want to move both with the camera and the object. It means that if originally I see a cube with the front face in a position when I move the cube up-down-left-right I want to see the object the cube with the faces in the same position. It means that if originally I see  a line like this \   when I move the object up /    \ I don't want to see the line like this / , on top of my camera.I hope I made myself clear.   ;  If you're using Open GL, you have 2 options:Open GL 1/2 (no shaders)//C/C++ CodeglMatrixMode(GL_PROJECTION);glLoadIdentity();// set up your projection matrix (ortho / frustum)glMatrixMode(GL_MODELVIEW);glLoadIdentity();// set up the camera's view here (translate (negative position values) /rotate)glPushMatrix();// set up the object's view here (translate / rotate)glPopMatrix();Open GL 2/3/4 (with shaders)//GLSL Codeuniform mat4 projectionMatrix;uniform mat4 modelviewMatrix;uniform mat4 objectMatrix;void main(){  gl_Position = projectionMatrix * modelviewMatrix * objectMatrix * gl_Vertex;};  Gorax, thank you for your reply. Unfortunately, I'm not using Open GL, I'm using Direct3D. I want to understand how to do this geometrically. I'm missing something and I don' know what.   ;  You may be talking about orthographic projection. You can build an orthographic projection matrix in OpenGL with glOrtho. Direct3D has a similar function.   ;  Venzon, you are right. That was what I needed. Thank you very much for your help. It is most helpful. Madalina   