Opacity based on orientation from the camera

We’re working on custom contrails. We managed to make them look amazing when seen from front/back but the illusion breaks when viewed from the side, where the particles can be seen as 2d billboards.

We are forced to use fixed orientation for this because of the swirls and the atlas texture we use. If the particles are facing the camera, the swirls would be inverted when seen from one side or the other.

It would be awesome to have the option to fade the particle out when seen from the side or be able to provide a separate texture that would be blended in when seen from the side (similar to how the trees work). This is also applies to ribbons, where artefacts can be seen from certain angles.

Thank you!

Had a thought while sleeping… a Vector3 Block called CameraDirection with -1 to 1 for each axis. That way we can apply this to anything!