The established correspondences is in turn allow to find an approximate viewpoint of the 2D depiction with respect to the 3D model.
This command works with perspective guide lines.
1. Vanishing point bar:
The two red bars with dashed lines should match characteristic edges on the photo on one side, and the two green bars with dashed lines should match lines on the other side. You find square marker on each end. Click and drag the grips to align these bars with characteristic edges on the photo.
Note: Use the zoom in and out commands with the mouse wheel to make sure your lines are as accurate as possible.
2. Horizon line:
This blue horizontal line aligns with the horizon in your model. You can move up and down the horizon line according to the photo but most of the times the horizon line takes care of itself.
3. Axis bars:
The solid green, red, and blue lines represent each axis. As you adjust the vanishing point bars, the axis bars move automatically
4. Axis origin:
The origin is where the three axes meet. Click on this marker and drag to align this point to locate the 3D model propertly on the photo.
5. Scale marker:
Click on this marker and drag up and down the blue axis bar to scale the 3D model on ther photo.
6. Turn and move marker:
Click on this marker if you wish to rotate the model with 90 degrees or relocate it with a specific point.