[x3d-public] Some screenshots with PhysicalMaterial and glTF

[Michalis Kamburelis]

As a teaser before next Friday, let me share some images I
generated yesterday and today :)

The new lighting model really looks pretty when used correctly (when
you supply various textures to vary details across the surface).
https://github.com/KhronosGroup/glTF-Sample-Models/ contains a number
of examples. Rendering of latest Castle Game Engine and view3dscene
can be compared with glTF-Sample-Viewer.

Here are 2 screenshots from view3dscene showing various glTF models:

- https://castle-engine.io/wp/wp-content/uploads/2020/03/FlightHelmet_0.png

- https://castle-engine.io/wp/wp-content/uploads/2020/03/DamagedHelmet_0.png

As an experiment, compare how the FlightHelmet looks like:

- With PhysicalMaterial in X3D v4:
https://castle-engine.io/wp/wp-content/uploads/2020/03/FlightHelmet_physical.png

- With (Phong) Material in X3D v4 (so with diffuse and normal
texture): https://castle-engine.io/wp/wp-content/uploads/2020/03/FlightHelmet_phong_v4.png

- With (Phong) Material in X3D v3 (only diffuse):
https://castle-engine.io/wp/wp-content/uploads/2020/03/FlightHelmet_phong_v3.png

Here's a demo that metallic/roughness works in CGE consistently with
glTF-Sample-Viewer (just the light source in glTF-Sample-Viewer is
different than view3dscene headlight):

- https://castle-engine.io/wp/wp-content/uploads/2020/03/metallic_roughness_view3dscene.png

- https://castle-engine.io/wp/wp-content/uploads/2020/03/metallic_roughness_gltf_sample_viewer.png

P.S. I'm working now on EnvironmentLight node, to perform image-based
lighting -- both for Phong and physical lighting model.

Regards,
Michalis