Hello! If I think I understand you questien right you are looking for extensions? If you click on “Window” the top bar in sketchup and under Window you click “Extension Warehouse” you will find extensions. But you can also just google for “Sketchup extensions” and you will find alot 
Caustics, I like to promote the word reflactive 
Translucent geometric reflective refraction hue indices of shade gradation seems a bit much.
No actually next to the ‘‘window’’ menu ‘‘Extensions’’ I mean Extensions menu