- ra3.map: capture the object RoadType; ra3.models pairs the map's
Start/End road objects and drapes a flat textured ribbon along each
segment (tessellated to the relief).
- Ground decals (roads/sidewalks) get a per-vertex screen-space depth
offset (scene::vertex.bias) applied in the object shader and the
software rasteriser, so they no longer z-fight or clip into the
terrain at top-down angles.
- Tactical view aligned with retail (SAGE LookAtTranslator): middle-drag
orbits yaw/pitch, a middle click resets angle/pitch/zoom, arrow keys
pan, wheel zooms within the retail zoom range; WASD pan removed and
left-drag no longer rotates.
- ui_event gains middle/right/released buttons; Vulkan + SDL map them.
- docs: roads, depth bias and camera controls.