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### #Actualuzipaz

Posted 19 August 2012 - 06:07 AM

@Ignifex

As you suggested, I will take a look at quaternions, I never heard this term before.

As far as camera and inverse transformations are concerned, this is what I am trying to do here already, the knowledge that I have with Opengl and viewing transformations come from the red book.

From what I understand, there is no such thing called a 'Camera' in Opengl library. If you want view an object that is drawn and centered at the origin, then you can either use the gluLookAt(0, 0, +z, 0, 0, 0, 0, 1, 0) or insted you can use glTranslatef(0, 0, -z), both of these will have the same effect (for this case at least).

From what I have studied and understand, the function name " LookAt " is like a false advertisement. You are not actually looking somewhere in the scene, it just applies inverse transformations to the whole scene and you think that you are moving a camera in the scene when you are acutally just transforming the scene. But then again, I might be incorrect here and its a completely different debate.

In my class, I am doing a similar thing, taking vector input in euclidean space and then finding the appropriate angle of rotations of heading and pitch, and then apply the inverse of this when I am rotating about an axis and it works fine as I please.

The problem I am having, is that if you take a look at my code, as long you give the initial arguments such that your hypothetical camera is located at the XZ plane, the heading will work fine, however, If I pitch or Roll to 180 degrees, and then I apply my heading calculation, then they will seem to work in reverse order. If I give the input to turn left, it will turn right and vice versa, because I am still rotating around this +ve y-axis.

Please note that, when I was trying to implement this class, I was not thinking in terms of matrices, I was thinking in terms of these transformation commands (glRotatef and glTranslatef).

### #1uzipaz

Posted 19 August 2012 - 06:05 AM

@Ignifex

As you suggested, I will take a look at quaternions, I never heard this term before.

As far as camera and inverse transformations are concerned, this is what I am trying to do here already, the knowledge that I have with Opengl and viewing transformations come from the red book.

From what I understand, there is no such thing called a 'Camera' in Opengl library. If you want view an object that is drawn and centered at the origin, then you can either use the gluLookAt(0, 0, +z, 0, 0, 0, 0, 1, 0) or insted you can use glTranslatef(0, 0, -z), both of these will have the same effect (for this case at least).

From what I have studied and understand, the function name " LookAt " is similar a false advertisement. You are not actually looking somewhere in the scene, it just applies inverse transformations to the whole scene and you think that you are moving a camera in the scene when you are acutally just transforming the scene. But then again, I might be incorrect here and its a completely different debate.

In my class, I am doing a similar thing, taking vector input in euclidean space and then finding the appropriate angle of rotations of heading and pitch, and then apply the inverse of this when I am rotating about an axis and it works fine as I please.

The problem I am having, is that if you take a look at my code, as long you give the initial arguments such that your hypothetical camera is located at the XZ plane, the heading will work fine, however, If I pitch or Roll to 180 degrees, and then I apply my heading calculation, then they will seem to work in reverse order. If I give the input to turn left, it will turn right and vice versa, because I am still rotating around this +ve y-axis.

Please note that, when I was trying to implement this class, I was not thinking in terms of matrices, I was thinking in terms of these transformation commands (glRotatef and glTranslatef).

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