Image (incomplete) is part of a project undertaken by external study of a couple of years ago, when I approached to Indigo for the first experiments. The scene has been found in 3Dwarehouse base, and was then made usable for the purpose of rendering after the usual series of inevitable alterations that make it almost always required when you use a template from that resource. In most cases it is normal to adjust the surfaces. SketchUp, as you know and it is easy to understand if you've tried at least once, working with two-dimensional surfaces, rather than primitive densities (cube, cone, cylinder, torus ,...) as many modeling applications: this gives it the versatility that we all know. The faces are always two sides to create a "straight" and a "reverse", so to speak. The "straight" and "wrong" are defined by an imaginary carrier - in fact - normal to the surface, so that the "straight" is identified as the outgoing side of the carrier, while the "other side" is intended to exclude the 'other side. One way to realize quickly normal wrong is to temporarily enable the monochrome view of SketchUp: the white faces have the correct standard, their faces blue / purple have reversed the normal. Per invertire le normali è sufficiente cliccare con il tasto destro del mouse sulla faccia viola e selezionare dal menu contestuale " Reverse face " o "Inverti faccia". Evidentemente non si tratta di un processo complicato, ma spesso risulta parecchio dispendioso in termini di tempo. Il problema delle "facce inverse" non coinvolge direttamente SketchUp, se il file viene gestito solo internamente al programma: sorgono invece molti conflitti quando lo stesso modello viene utilizzato allo scopo del rendering. Spesso i materiali applicati alle facce inverse non vengono riconosciuti: così otterremo una superficie bianca nella nostra immagine, nel migliore dei casi; se il materiale che avevamo impostato è invece un vetro o un altro dielettrico 99% of the cases we get a completely black face.
