Merge pull request #1570 from EIREXE/master

Add recommendation to disable sky contribution to spatial material doc toon diffuse mode explaination.

tutorials/3d/spatial_material.rst

@@ -138,7 +138,7 @@ default one is Burley. Other modes are also available:
 * **Lambert:** Is not affected by roughness.
 * **Lambert Wrap:** Extends Lambert to cover more than 90 degrees when roughness increases. Works great for hair and simulating cheap subsurface scattering. This implementation is energy conserving.
 * **Oren Nayar:** This implementation aims to take microsurfacing into account (via roughness). Works well for clay-like materials and some types of cloth.
-* **Toon:** Provides a hard cut for lighting, with smoothing affected by roughness.
+* **Toon:** Provides a hard cut for lighting, with smoothing affected by roughness. It is recommended you disable sky contribution from your environment's ambient light settings to achieve a better effect.
 
 .. image:: img/spatial_material6.png