What are the preferred methods for getting the full shadow of a 2D image as plane using only a HDR background and no lamps when they need to face towards the camera for best viewing angle but are side on to the light source as in the left rear tree in my pic?
2 rear trees are angled -40 and +40 respectively to face the camera.
Using 3 or 4 planes (as in the foreground) there is often a point where the planes are noticeable in an animated camera movement
BTW this is not actual viewing angle but a demonstration of the effect
This isn’t something I do, so far outside my comfort zone. But i might try shadow invisible plane always facing the camera, and a shadow visible only plane facing the major lightsource, maybe using an empty and constraints?
For now I’m duplicating and rotating them on a separate layer so I can render the shadows but not the plane. It can get a bit messy when I render a dozen different alpha layers for later compositing. Especially if there are multiple layers with trees that only need shadows rendered. Extra layers means extra render time
