message: remove postIntersect code path for non-instances
  [ci skip]
diff: @@ -105,7 +105,6 @@ inline void postIntersect(const World *uniform model,
  dg.primID = ray.primID;
  dg.st = make_vec2f(ray.u, ray.v);
  - // iw: note - this code does not yet work with instances
  dg.materialID = -1; // make sure this is properly initialized
  dg.material = NULL;
  @@ -120,29 +119,13 @@ inline void postIntersect(const World *uniform model,
  dg.P = ray.org + ray.t * ray.dir;
  dg.epsilon = 0.f; // per default no geometry-type specific epsilon
  - // a first hack for instancing: problem is that ospray assumes that
  - // 'ray.geomid' specifies the respective sub-geometry of a model
  - // that was hit, but for instances embree actually stores this value
  - // in ray.instID, so the model would have to know if it's a model
  - // over instances or a model over geometries, which is kind of ugly
  - // ... will eventually have to fix this properly by implementing
  - // instances directly in ospray, but for now let's try this hack
  - // here:
  - if (ray.instID == RTC_INVALID_GEOMETRY_ID) {
  - // a regular geometry
  - foreach_unique(geomID in ray.geomID) {
  - uniform Geometry *uniform geom = model->geometry[geomID];
  - dg.geometry = geom;
  - geom->postIntersect(geom,model,dg,ray,flags);
  - if (geom->materialList) {
  - dg.material = geom->materialList[dg.materialID < 0 ? 0 : dg.materialID];
  - }
  - }
  - } else {
  + if (ray.instID != RTC_INVALID_GEOMETRY_ID) {
  foreach_unique(instID in ray.instID) {
  GeometryInstance *uniform instGeom = model->geometryInstances[instID];
  GeometryInstance_postIntersect(instGeom, model, dg, ray, flags);
  }
  + } else {
  + dg.Ns = dg.Ng = ray.Ng;
  }
  // merge geometry-type specific epsilon with general epsilon
  @@ -154,7 +137,6 @@ inline void postIntersect(const World *uniform model,
  #define DG_NG_NORMALIZE (DG_NG | DG_NORMALIZE)
  #define DG_NS_NORMALIZE (DG_NS | DG_NORMALIZE)
  -
  vec3f ffnng = normalize(dg.Ng);
  cif ((flags & DG_NG_NORMALIZE) == DG_NG_NORMALIZE)
  