koplersky

10-13-2013, 05:48 PM

Hello there,

I've read many tutorials about drawing and coordinates systems.

I understood the theory about matrix transformations and how to draw simple objects to the screen.

But I don't understand how is drawing related to the different coordinates systems.

I've specified the triangle vertices coordinates, for example. After drawing it, how do I know which coordinate system they are drawn to?

I'm using shaders.

In the vertex shader, the gl_Position is being assigned to the vPos in variable which was multiplied by the transformation matrices (I know the order matters here).

But by doing that does OpenGL is aware that my object was in another coordinate system or does it always supposed I have vertices in device coordinates?

How should the vertices be specified before doing further transformations?

I'm very confused about this and would really appreciate any advices or links.

I've read many tutorials about drawing and coordinates systems.

I understood the theory about matrix transformations and how to draw simple objects to the screen.

But I don't understand how is drawing related to the different coordinates systems.

I've specified the triangle vertices coordinates, for example. After drawing it, how do I know which coordinate system they are drawn to?

I'm using shaders.

In the vertex shader, the gl_Position is being assigned to the vPos in variable which was multiplied by the transformation matrices (I know the order matters here).

But by doing that does OpenGL is aware that my object was in another coordinate system or does it always supposed I have vertices in device coordinates?

How should the vertices be specified before doing further transformations?

I'm very confused about this and would really appreciate any advices or links.