How to render the shadow of an invisible object? Say I wanted to make a render of a ghost. The ghost must be invisible to the camera, but it must still cast a shadow on the ground. How can I block light from passing though an object that is invisible?
If you are using cycles you just have to disable camera visibility.





Alternatively you can make a shader that uses the camera ray as a mix factor for your figure's shader and a transparent one. The camera will not see the object but it will still cast a shadow.