Perspective Matching allows you to interactively match the Perspective camera to the camera with which a background image was taken. In order to activate Match Perspective, please load a Backplate. Refer to Changing the Background for further information on this topic.
When clicking on the Match Perspective button, you will notice 2 or 3 sets of lines in different colors along with a dialog.
For best results we recommend to turn on Show Coordinate Legend, found under the View menu. It can also be toggled on and off using the Z hotkey. This will help you identify the orientation of the model in the scene.
How it works:
Decide whether you want to use 2 or 3 point perspective, i.e. 2 or 3 vanishing points. In most cases you want to use a 2 point perspective. 3 point perspective is most commonly used when trying to place building or object when the camera is placed at a low of high eye level. When using 2 point perspective, you will only adjust the vanishing according to the plane on which the object is placed. 3 point perspective adds another set of lines allowing you to adjust the vanishing point in the vertical direction.
Notice that the lines and colors correspond to the scene's coordinate system. X is blue, Z is red, and Y is green. Move the end points of the lines according to the coordinate layout to reference points in the background image. Notice the camera values update accordingly. Once aligned, pan and dolly the camera to position the object so it fits properly inside the scene.
Adjust the perspective with 2 sets of orthogonal lines to match the vanishing points of a background image.
Adjust the perspective with 3 sets of orthogonal lines to match the vanishing points of a background image.
Turn on ground grid in the scene to help match the perspective.
Reset all sets of lines to their default position. The camera will update accordingly.