page updated: 2011.10.08

CAMERA-MATCH tool will help you to adjust camera to your reference picture in Blender.
You do not need parameters from the camera originally used - the tool will recalculate
all necessary parameters from picture: Location, Orientation, Lens (FocalLenght) and Shift.
It will work well for pictures with some orthogonal elements - especially for architectural motives.

Feature video (CADtools 0.55 beta - 2010.12.27)

USAGE: How to match camera to a reference-image?

1. Select Background-Image and Camera
	- Select and acivate your Background-Image:
	  You can do this here with Image-menu (CAD-edition only)
	   or manually in 3d-View->View->Background_Image panel.
	- Select nay perspectie Camera or create a new one and set it as active_camera:
	  You can do this here from within Camera-List (with CAD-edition only)
	  or manually in 3d-View.
	- You can also select an "Image-Camera"-item stored to the List before.

2. Match Camera to Reference Background-Image
	You must manually set vanishing-points for particular directions X,Y,Z.
	Choose one of the methods:
	   a. draw up to 3 vanishing-points directly in camera view plane.
	   b. draw up to 3 pairs of parallel lines, which estimate vanishing-points due virtually crossing on horizon.
	There are three scenarios possible:
	   - draw "one point" for central-perspective (works for pictures taken exactly in front of an object)
	   - draw "two points" for two-vanishing-points-perspective (script assumes the camera focal axis is horizontal)
	   - draw "three points" for three-vanishing-points-perspective (most common case - a free camera position)
	After completing this step the routine updates Camera parameters. The Camera is now calibrated.
	The position of Background-Image in camera may change by cropped/shifted images.
	An extra object will appear - the reference mesh "RefCube". It looks like a "house",
	to give you better visual feedback about its XYZ-orientation.
	Move or scale it to get impression about correctness of camera calibration.
	To get perfect results in some situations you will need to repeat above procedure.
	
3. Align back Camera/Image to your model/scene
	"RefCube" object will help you to align your calibrated Camera to your model in Blender.
	Follow these steps: 
	a. Transform RefCube to match the context of your Background-Image.
		Use move, scale, mirror and 90-degrees-rotate.
	b. Align RefCube+Camera to your model in Blender.
		The routine will assist you on this way:
		It selects RefCube and Camera and starts for you
		ALIGN-command with RefCube's ObjectMatrix as startMatrix
		and with current UCS as targetMatrix. 
		You can make your own choices: e.g. change targetMatrix.
		After confirmation RefCube and Camera will be rotated and moved to the right location.
	 c. Re-scale RefCube+Camera until the Reference-Image becomes congruent to your model.

4. Finally
	You can store current BgImage+Camera-Set under individual name for future use.
	You can delete "RefCube" now - it will be recreated automatic next time.
	"RefCube" name is reserved for camera-matching helper object,
	so better rename it and its obData before start modeling with it.
	

Additional Notes
	This tool supports shifted and cropped reference images.
	It doesn't work for anamorphic images and optics.