Assimp
v3.0 (July 2012)

Helper structure to describe a virtual camera. More...
Public Member Functions  
aiCamera ()  
void  GetCameraMatrix (aiMatrix4x4 &out) const 
Get a righthanded camera matrix from me. 
Public Attributes  
float  mAspect 
Screen aspect ratio.  
float  mClipPlaneFar 
Distance of the far clipping plane from the camera.  
float  mClipPlaneNear 
Distance of the near clipping plane from the camera.  
float  mHorizontalFOV 
Half horizontal field of view angle, in radians.  
aiVector3D  mLookAt 
'LookAt'  vector of the camera coordinate system relative to the coordinate space defined by the corresponding node.  
aiString  mName 
The name of the camera.  
aiVector3D  mPosition 
Position of the camera relative to the coordinate space defined by the corresponding node.  
aiVector3D  mUp 
'Up'  vector of the camera coordinate system relative to the coordinate space defined by the corresponding node. 
Helper structure to describe a virtual camera.
Cameras have a representation in the node graph and can be animated. An important aspect is that the camera itself is also part of the scenegraph. This means, any values such as the lookat vector are not absolute, they're relative to the coordinate system defined by the node which corresponds to the camera. This allows for camera animations. For static cameras parameters like the 'lookat' or 'up' vectors are usually specified directly in aiCamera, but beware, they could also be encoded in the node transformation. The following (pseudo)code sample shows how to do it:

inline 

inline 
Get a righthanded camera matrix from me.
out  Camera matrix to be filled 
todo: test ... should work, but i'm not absolutely sure
We don't know whether these vectors are already normalized ...
float aiCamera::mAspect 
Screen aspect ratio.
This is the ration between the width and the height of the screen. Typical values are 4/3, 1/2 or 1/1. This value is 0 if the aspect ratio is not defined in the source file. 0 is also the default value.
float aiCamera::mClipPlaneFar 
Distance of the far clipping plane from the camera.
The far clipping plane must, of course, be further away than the near clipping plane. The default value is 1000.f. The ratio between the near and the far plane should not be too large (between 100010000 should be ok) to avoid floatingpoint inaccuracies which could lead to zfighting.
float aiCamera::mClipPlaneNear 
Distance of the near clipping plane from the camera.
The value may not be 0.f (for arithmetic reasons to prevent a division through zero). The default value is 0.1f.
float aiCamera::mHorizontalFOV 
Half horizontal field of view angle, in radians.
The field of view angle is the angle between the center line of the screen and the left or right border. The default value is 1/4PI.
aiVector3D aiCamera::mLookAt 
'LookAt'  vector of the camera coordinate system relative to the coordinate space defined by the corresponding node.
This is the viewing direction of the user. The default value is 001. The vector may be normalized, but it needn't.
aiString aiCamera::mName 
The name of the camera.
There must be a node in the scenegraph with the same name. This node specifies the position of the camera in the scene hierarchy and can be animated.
aiVector3D aiCamera::mPosition 
Position of the camera relative to the coordinate space defined by the corresponding node.
The default value is 000.
aiVector3D aiCamera::mUp 
'Up'  vector of the camera coordinate system relative to the coordinate space defined by the corresponding node.
The 'right' vector of the camera coordinate system is the cross product of the up and lookAt vectors. The default value is 010. The vector may be normalized, but it needn't.