texture projection paint settings in blender I wanted to use texture projection for camera as described by In this series. However the explanation of the settings used is not described in his video clearly. Particularly this setting which is found under the Project Paint panel in texture paint mode:   



The tooltip says: "Paint most faces pointing towards the view according to this angle. "  

My question is: How is this angle affecting the projection? Is it the angle of the camera with the surface of the meshes?

Please do explain in detail what this angle is and how it affects the texture projection. Some illustrations would be helpful. Thanks in advance.
It is the angle between the surface's normal and the vector from the surface to the camera (an orthographic view vector).


Top view.  

This means the angle is small for faces pointing directly at us and larger for face viewed at an angle.

If you wish to exclude surfaces which are not viewed directly from the from, decrease the normal angle value.


I think the inaccuracy is due to the large brush and the bleed settings, but the idea should be clear.

While texturing from a camera projection you usually want a low normal angle. From the camera view the faces oriented away from the camera, will have less pixels per surface and the texture will be more distorted. Use a low normal value to avoid painting on the, then paint on them from a more perpendicular viewing angle with a different reference image.