Viewport and Render Preview / Maya
From this guide you can learn how to configure Maya viewport to match Verge3D look and feel and how to use the Arnold rendering to obtain a reference image.
Viewport Settings
To enable better viewport preview in Maya, enable Hardware Texturing in the viewport settings:

Also switch lighting from Use Default Lighting to Use All Lights (or press 7 shortcut):

The above-mentioned settings are pre-enabled for the default cube project.
Viewport shading, however, does not always appear to provide an accurate approximation of the in-browser rendering. Hence, you might use the Arnold renderer (see below) or Verge3D's Sneak Peek feature to preview your scenes.
Color Management
By default Maya uses the ACES color encoding system (with ACEScg color space).

This system is not supported in Verge3D, since it requires more powerful GPUs and not quite feasible for the real-time browser rendering.
The ACES will make your scenes look darker in Maya viewport compared to Verge3D:

To switch back to the regular sRGB-based color encoding, open the Maya preferences:

Go to the Color Management preferences, then click on the small arrow (▼) on the right side of the OCIO Config Path. Select Reset to Legacy, then click Save button to close the Maya preferences dialog.

Make sure that now Maya viewport is set to sRGB gamma (legacy) view transform:

The sRGB-based color encoding is pre-enabled for the default cube project.
Arnold Rendering
Verge3D rendering strives to be as close as possible to Arnold render if Standard Surface or Open PBR materials are used. So you can preview your scenes in Maya without exporting for quicker tweaking.
To select the renderer, switch to Arnold in the Renderer menu:

Then wait until the renderer produces some feasible results:

Once something changed in your scene, Maya automatically updates the renderer results in the viewport. This way you can achieve a better approximation of what you get in the browser, at a near real-time speed.
Got Questions?
Feel free to ask on the forums!