Image-type fills (a 2D element) cannot receive shadows - only 3D elements can do so.
While you can set up an elevation to show the material color and fill linework, with shadows, you cannot have the elevation tool generate an image that shows the texture (image) assigned to materials.
In order to get shadow casting on a rendered elevation, you have to use an axo view in the 3D window - either OpenGL shadow casting, or a rendered image. You then have to fake the scaling, and if annotation is required you'll have to overlay an annotation drawing. Or some such workaround.
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB