[LibGDX]Do we really need OrthographicCamera?

[The_Lion_King]

@P0jahn

I am converting a pretty big engine. Switching every upward and downward movements is going to be a nightmare.

This is why OO design is so important…

Also a simper fix is just deal with the “backwards” y axis.

[pitbuller]

@Troubleshoots

@The_Lion_King

This makes no sense.

Its a perspective matrix. There is no translation or rotation.

I’m not sure what you mean. The Camera class holds a view and a projection matrix. The view matrix is the combined translation, rotation and scale transformation whereas the projection matrix is set to the orthographic projection matrix.

i.e the view matrix describes the camera orientation and the projection matrix describes the camera lens (field of view, zoom, etc.)

Just to note here that View matrix is inverse of camera transformation.

[Troubleshoots]

@pitbuller

@Troubleshoots

@The_Lion_King

This makes no sense.

Its a perspective matrix. There is no translation or rotation.

I’m not sure what you mean. The Camera class holds a view and a projection matrix. The view matrix is the combined translation, rotation and scale transformation whereas the projection matrix is set to the orthographic projection matrix.

i.e the view matrix describes the camera orientation and the projection matrix describes the camera lens (field of view, zoom, etc.)

Just to note here that View matrix is inverse of camera transformation.

And to explain why, it’s because when you’re transforming the camera, you’re actually transforming the vertices of all the meshes in the “world” (in space). The camera does not exist, it’s simply an object that calculates and holds the matrices which describe the transformation of vertices. Matrices are used since they simplify the calculations that are needed to describe a transformation. When you want to translate “the camera” on the X axis +100px, you’re actually wanting to transform all the vertices that are drawn in the world -100px.

[pitbuller]

Camera is real object in same sense than anything else. You can use all the same code for calculating its transform than for rest of objects. But then you just calculate view matrix by taking the inverse of its transform matrix.