EEVEE-Next: New shadow settings

Remove `Material > Shadow Mode` and use `Object > Shadow Ray Visibility`
and `Material > Transparent Shadows` instead.

The versioning system auto-updates objects/materials in EEVEE
scenes so their behavior is as close as possible to the previous one.

Update Cycles to use the native `use_transparent_shadow` property.

Note:
Material changes don't set any `recalc` flag on the objects that use
them, so the EEVEE Next shadow maps don't update when changing
settings/nodes.
Fixing this issue is required for 4.1, but it's out of the scope of this PR.

Pull Request: https://projects.blender.org/blender/blender/pulls/113980

scripts/startup/bl_ui/properties_material.py

@@ -300,7 +300,7 @@ class EEVEE_NEXT_MATERIAL_PT_settings_surface(MaterialButtonsPanel, Panel):
         col.prop(mat, "use_backface_culling_shadow", text="Shadow")
 
         # TODO(fclem): Displacement option
-        # TODO(fclem): Transparent shadow option
+        layout.prop(mat, "use_transparent_shadow")
 
         col = layout.column()
         col.prop(mat, "surface_render_method", text="Render Method")

scripts/startup/bl_ui/properties_object.py

@@ -390,6 +390,11 @@ class OBJECT_PT_visibility(ObjectButtonsPanel, Panel):
         col.prop(ob, "hide_render", text="Renders", toggle=False, invert_checkbox=True)
 
         if context.engine == 'BLENDER_EEVEE_NEXT':
+            if ob.type in {'MESH', 'CURVE', 'SURFACE', 'META', 'FONT', 'CURVES', 'POINTCLOUD', 'VOLUME'}:
+                layout.separator()
+                col = layout.column(heading="Ray Visibility")
+                col.prop(ob, "visible_shadow", text="Shadow", toggle=False)
+            
             if ob.type in {'MESH', 'CURVE', 'SURFACE', 'META', 'FONT', 'CURVES', 'POINTCLOUD', 'VOLUME', 'LIGHT'}:
                 layout.separator()
                 col = layout.column(heading="Light Probes")