Switching alphaMode from BLEND to MASK with a 0.5 cutoff lets the lampe
material participate in instanced shadow rendering correctly. BLEND is
known to interact badly with InstancedMesh shadow casting, producing
incorrect or missing shadows on the pylone lampe.
- gant_r/model.gltf: align casing with the actual files on disk
(gant_basecolor / gant_occlusionroughnessmetallic) so the GLTFLoader
stops logging 'Couldn't load texture' on case-sensitive filesystems
- pylone/model.gltf: nine missing Image_N.png references replaced with
the existing color.png / normal.png so the pylone renders without
console errors. Material slots are mapped by role: normalTexture ->
normal.png, baseColorTexture and metallicRoughnessTexture -> color.png
Tom Boullay