Added a new plugin useful for interacting with the elements of the scene via scripts in VB.NET language.
By pressing the Help button you can open a small manual with two examples, from which you can copy code fragments into the clipboard.

New rendering attribute "RenderClipArea", by default it will contain the rendering area expressed as xy starting point and xy ending point. It can be modified to render only a specific area.

Added a rendering attribute "RenderBackSurfaces", by default it is False but if set to True it renders the hidden surfaces of all objects. For loading scenes via plugin PBRT4 is set to True.
As you can see from the comparison alongside, the improvements are evident.
Other comparisons at the following link.
Also added a new attribute "BackfaceCulling" to all materials (only new ones in PBRT4 standard), by default it is True but if set to False it renders the hidden surfaces of the objects that have applied the material.

Added a new material to handle area light, and takes the place of the Light map of the BlinnOrenNayar material. You can apply this material to any instance to turn it into a light source.

Added the ability to load instances (possibility to replicate the shape while maintaining the same memory area for vertices and polygons, changing only the transformations and applied material) of the PBRT4 scenes. Given the high amount of memory it requires (even replicating the instance leads to an increase in the memory used) this feature is disabled by default. To enable it, an additional option has been added in the "PBRT4 Settings" plugin, detailed further below in the interface news.

Added a new ThinDielectric material in the PBRT4 standard, useful for simulating thin dielectric surfaces (e.g. transparent plastic Christmas tree decorations, bubbles, etc.).s

I finally implemented full spectrum rendering in the MultiplexedMLT render engine!
As can be seen from the comparison on the side, the colors will be more realistic.
More comparisons at the following link.
The use of Spectrum is active by default but can always be deactivated from the MultiplexedMLT engine attributes.

I implemented a new plugin to load PBRT4 scenes.
Some scenes can be downloaded in the Official PBRT git.
Next an example of a scene in pbrt format rendered using Now3D2.
More examples can be found in the gallery.

Thanks to the KDtree algorithm now you can render more complex scenes and those containing displacement materials faster! The use of the KDtree is optional (except for pbrt4 scenes where it is active by default) and can be applied from the rendering attributes, the previous Octree will soon be deprecated, and only the KDtree one will remain.

Implemented two new nodes useful for spectrum management.

• Spectrum: the input is a spectrum expressed as a string composed of wavelength/value pairs separated by space (e.g.: 298.757 1.795 302.4004 1.812)
• Blackbody: the input is the temperature of a black body (e.g. 5500 for the sun)

Thanks to this action applicable to the scene, it is possible to increase or decrease the size of the scene. This is useful in cases where the scene is smaller than unity (most pbrt4 scenes), as Now3D2 still doesn't handle scenes of that size well.