As far as I know only OBJECTS can cast (or receive) shadows: TEXTURES do not have those properties.
Here is what I found when typing "Shadows" into BTB (non-Evo) User Manual's search window:
Editing Objects
The editing of Objects refers to the placement, rotation and scaling of the Objects. BTB is not deisgned to edit the internal structure of an object, such as moving individual vertices. There are plenty of 3d editors that already do this very well.
Object Groups
The list on the left display the Object Groups and they are purely to help you organise things inside BTB, they do not affect the final export to game.
Singly-added Objects are included into the first selected existing Group. If no Group is selected it will be placed into the Default group.
Groups are automatically created and their names are assigned based on the tool used and the Objects selected at the time of creation.
Hide all but the selected Group(s) by ticking the Hide Unselected checkbox.
Merge one or more Groups by selecting them in the list, then clicking the Merge button. This will move all Objects into the first selected Group and remove all other selected Groups.
Select Objects from one or more Groups and click the Split button to move the Objects into a new Group.
Move
Select an Object by clicking on it, or by clicking in an empty space and lassooing the Object(s).
Hold Shift and left-click to multi-select or move all selected objects.
Hold C and left-click to copy selected objects.
By default Objects are set to Rest on Ground (see
Properties).
Hold the Y key to move an Object vertically. This is useful even if the Object is set to Rest on Ground.
Rotate
Select Objects as per the Move tool. 3 rings, Blue, Red and Green are displayed around each Object. Click on a ring and move the mouse left/right or up/down to rotate. The Blue & Red rings will tilt the Object, the Green ring affects the Objects Yaw.
Instead of clicking on the rings, you can hold X, Y or Z before clicking to limit the rotation to the one axis. Y will be most popular since it controls the Yaw.
Scale
Select Objects as per the Move tool. 3 lines, Blue, Red and Green are displayed extending from each Object. Click on a line and move the mouse in the direction of the line to scale the Object in that direction.
Align
This tool is very useful for aligning Objects near a track.
- Select the Objects you wish to align.
- Click on the Track you wish to align with and drag from side to side.
- Tick this to rotate the Objects so that the same side for each is towards the road. Enter a value in degrees to add additional rotation amount.
Properties
As you change these properties, the values are assigned to the selected Objects.
Rest on Ground Should BTB adjust the height so that the Object sits on the ground. Driveable The Object can be driven on. Collide If checked, you can collide with this Object. Moveable When checked, the Object will be moveable. When hit it can move like a Sign or like a Cone. Render The object will be rendered. Turn this off for things like invisible barriers. Always Render If checked, the Object will always be rendered. Recieve Shadows Determines if shadows are cast upon this Object. Receive Light Does the Object get brighter under lights (headlights). LOD In Minimum distance from viewpoint before the Object is drawn onscreen. LOD Out Maximum distance from viewpoint before the Object is drawn onscreen. Cast Shadow Will a shadow be cast by this Object? Dynamic = also falss on moving cars, Static = doesn't cast over cars. A Shadow Quality setting determine how fine/blocky the shadow is. Light stays on For a night light object, if checked this object will cast light during the day too.