fix(map): Set raycasting rendering options in Image3d initializer

The default rendering options for Image3d have colormap_on_gpu and
full_region_on_gpu set to false. This works fine for the shaders that
handle planes drawings, but raycast drawings need both options set to
true. One could previously make an Image3d with one of its default Planes
drawings and then switch to the Raycasting mode, and these two options
would be set to true in set_options. However, that function is not
called during initialization, and if they aren't set then the wrong
shader is compiled for an Image3d object trying to create a Raycast
drawing first. The user would get a nasty graphics traceback. This
commit sets those options during _auto_projection_mode, which is called
early enough.

Fixes Trac#16682

src/bundles/map/src/image3d.py

@@ -640,6 +640,9 @@ def _auto_projection_mode(self):
                 pm = ("2d-x", "2d-y", "2d-z")[list(s).index(smin)]
             else:
                 pm = "3d"
+        if pm == 'rays':
+            self._rendering_options.colormap_on_gpu = True
+            self._rendering_options.full_region_on_gpu = True
         return pm
 
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