Material System Overview

To some extent, Verge3D supports the following types of materials available in Blender:

Standard materials

These are default materials in Blender 2.7. They allow for tweaking basic settings and adding textures. Generally, standard materials are not recommended for use, unless you are doing something simple or just experimenting.
In the upcoming Blender 2.8, these materials will no longer be available. Please consider using PBR or Cycles materials for new projects if you are working in Blender 2.7.

Node-based GLSL materials

These are powerful and flexible materials used in Blender 2.7. Some early Verge3D demos and the stock material library are based on GLSL nodes (as of November 2018).
Material parameters can be animated or changed with Puzzles or with code using Value or RGB nodes.
In the upcoming Blender 2.8, these materials will no longer be available. The material library will eventually be upgraded to Eevee to become available to all library owners free of charge. Please consider using PBR or Cycles materials for new projects if you are working in Blender 2.7.

glTF-compliant PBR

These materials follow glTF 2.0 standard for physically based materials (PBR). According to this standard, material information is encoded in a set of textures: base color, occlusion-roughness-metallic packed in R, G and B channels respectively, and normal.
In Verge3D, glTF-compliant PBR materials are represented with a Cycles-based node group, to inputs of which PBR textures are connected (click on the image below to enlarge).
This node can be appended from the NodeTree category of the storage file verge3d/applications/materials/pbr_material.blend. Make sure that its name, "Verge3D PBR", is left intact during this procedure.
In addition, although this is not part of the glTF 2.0 standard, you can set up world nodes to serve as environment. The environment will be ignored by glTF-compliant loaders such as Facebook News Feed.
Please refer to Physical material section of this User Manual for more information on how to set up these materials.

Cycles materials

Cycles is Blender's raytracing renderer and can be recreated in real-time rendering engines such as Verge3D only approximately. Nevertheless, the support for Cycles in Verge3D allows you to transfer your existing Cycles-based assets online without much hurdle.
Material parameters can be animated or changed with Puzzles or with code using Value or RGB nodes.
As of November 2018, not all Cycles nodes are supported by Verge3D. Particularly, the following complex shaders are not supported: Anisotropic BSDF, Ambient Occlusion, Glass BSDF, Hair BSDF, Holdout, Principled Hair BSDF, Principled Volume, Refraction BSDF, Subsurface Scattering, Toon BSDF, Translucent BSDF, Velvet BSDF, Volume Absorption and Volume Scatter. The following procedural textures are not supported: Brick Texture, Gradient Texture, Magic Texture, Musgrave Texture, Point Density and Wave Texture.

Eevee materials

Eevee is a real-time renderer which is currently under development as part of the upcoming Blender 2.8. Eevee is expected to become the main authoring tool in the future versions of Verge3D.
Material parameters can be animated or changed with Puzzles or with code using Value or RGB nodes.
In addition to materials, Blender's Eevee-based viewport will offer post-process effects such as ambient occlusion (AO), depth of field (DOF), subsurface scattering (SSS), Bloom, SSR (screen space reflections) and others. Al least some of these post-process effects will be available in Verge3D as well.
In Blender 2.8, Cycles nodes will be interchangeable with Eevee's, so you it is a good idea to start using Cycles nodes for new projects if you are working in Blender 2.7. This will make future conversions straightforward.