When you translate, you are not moving a set amount from the center of the screen, you are moving a set amount from wherever you currently were on the screen. It does not move on the Y axis at all (0.0), and it moves into the screen 6.0 units. The line of code below moves left on the X axis 1.5 units. GlTranslatef(x, y, z) moves along the X, Y and Z axis, in that order. Moving deeper into the screen is a negative number, moving towards the viewer would be a positive number. Moving towards the top of the screen would be a positive number, moving to the bottom of the screen would be a negative number. To the left of center would be a negative number. The center of an OpenGL screen is 0.0f on the X and Y axis.

When you do a glLoadIdentity() what you are doing is moving back to the center of the screen with the X axis running left to right, the Y axis moving up and down, and the Z axis moving into, and out of the screen. GlClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) // Clear The Screen And The Depth Buffer int DrawGLScene(GLvoid) // Here's Where We Do All The Drawing If you plan to modify the last lesson, you can replace the DrawGLScene() procedure with the code below, or just add the lines of code below that do not exist in the last tutorial. I will rewrite the entire procedure below. Using the code from the first tutorial, we will be adding to the DrawGLScene() procedure. We will create a triangle using GL_TRIANGLES, and a square using GL_QUADS. In this tutorial I will teach you how to create both Triangles and Quads. In the first tutorial I taught you how to create an OpenGL Window.

Java lwjgl drawing 3d polygon tutorials