One is the diffused image, the other one is the normal map of the first image. This is similar to Bump maps, but much better.

Set the material as a background image, where it receives no light, nor does it emit light. If you use a Normal map (see below) the image is used, not the color. The dark spot will appear caved in while brighter spots will appear more elevated from the surface. When using an image for a material (without normal map), such as bricks, and setting a value for Bump level, only the color of the material will be used, but, the actual image will be used to produce a bumpy surface. Depending on the angle you view it, the straw will appear broken in half, or even shorter than its actual length. Such phenomenon can be observed by looking at a glass of water with a straw in it. Refraction is the effect of light entering an object and bending, possibly reflecting and bending again before exiting the object. Click on the icon next to it to select a predefine value, or enter one for other types not listed. Sets the IOR (index of refraction) of the material, such as glass, water and plastic. Sets the amount of light that is reflected off the surface. It can also be used without refraction, but in real life, any transparent material do produce some refraction. Sets the amount of light that can go through the object when using refraction such as in glasses and plastics. They are not directly reflective, but they are shinny. Such object are bathtubs and wood floors for example. It works on different principals to produce real shininess rather than being reflective. This is not like pure reflection but similar. Set how shiny a material is by using its IOR (index of reflection). The higher the number, the less polish the surface will be.

Set the texture irregularity of the material. For example, to make a mirror, set the Reflection to 1 for 100% reflective. This is the option you will most likely use. If you leave it in the 'Off' position, this selected material will not emit any light when rendering your model. If you want the selected material to be a light source other than the sun and sky, select this option and select 'On', then set the power of the light source along with the coverage angle. 'User Defined' and 'Light/Emitter' as described below. Now you can make changes to the selected material using one or more combination of the following. The selected material name will be displayed in the 'Raylectron Material Editor' window. Next, select a material from the 'Sketchup Materials' window, or use the Sketchup 'Sample paint' picker to directly select a material from your model.

First, bring up the 'Raylectron Material Editor' (if not already opened) from the Sketchup 'View / Raylectron Render' menu. It is very easy to apply some styles to your materials.

Raylectron v4