9.27 Perspective

Sets up the mapping from the 3D world to the view point of the camera, where objects that are farther away appear smaller.

This effect is usually declared as a muvee-global-effect. If you don’t use Perspective as a global effect, the visible size of an object will be a constant - independent of its distance from the camera. (Such a projection is called “orthographic projection”.)

	Parameters		Default		Range		Description
	fovy		45.0		[0.0, 90.0)		The field of view, expressed in degrees. Conceptually, it means how wide do we want our camera lens to be.
	zNear		0.1		> 0.0		This and the next parameter define z clipping planes. Objects closer to the camera than zNear are clipped and so are objects farther from the camera than zFar.
	zFar		10.0		> 0.0		zFar is conceptually the back of our clipping box.

9.27.1 Examples

9.27.1.1 Behaviour as an image is moved along the z-axis in Perspective Mode

; muSE v2

;

;  My super awesome style.

;  This style uses the Perspective effect and demonstrate

;  what happens when we move our image further back in the z-axis.

(style-parameters)

(segment-durations 8.0)

(define muvee-global-effect (effect-stack

(effect "Perspective" (A))

(effect "CropMedia" (A))))

(define muvee-segment-effect (effect "Translate" (A)

(param "z" 0.0 (linear 1.0 -5.0))))

Our main focus is the muvee-global-effect. That’s where the Perspective effect has been declared. Now, what we’re doing in the segment-level-effect is simply move the user image further in the z-axis as the segment duration progresses along. To fully appreciate the meaning of perspective, run the above style once; Then run it again after deleting the line (effect "Perspective" (A)).

Do note that many styles declare CropMedia and "Perspective" as Global Effects. This is a rather standard procedure and you are encouraged to do the same.