Boxshot supports a lots of reflection features by the small number of parameters, so it is relatively easy to get used to them and get good results really fast.
There are several controls in the Reflection section of the Materials panel:
- Fresnel reflection - controls the Fresnel reflection mode (see below)
- Raytraced reflection - switches between texture and environment reflection
- Level - define the level of reflection
- Level mask - a grayscale map that allows you to have different reflection level in different places of the material
- Blur - controls how rough is the reflective surface
- Blur mask - a grayscale map that controls the blur level over the shape
- Samples - controls how many rays to trace when computing reflection
- Reflection texture - defines a texture to reflect
- Tint - a color to multiply the reflection result
If the user doesn't check the Raytraced reflection, Boxshot will not trace reflection rays for the surface, it just applies the texture instead.
If the user checks that box, the more complex algorithm is used. Boxshot traces reflection rays for the surface and if rays hit something, the surface reflects this. Otherwise if rays don't hit another surface, Boxshot computes the reflection using the reflection texture. If there is no reflection texture, Boxshot uses environment background texture and color.
From the left to right, the first sphere does not reflect at all. The middle one has texture-based reflection and the right one reflects environment. Please note that the right sphere also reflects the middle one, while the middle one doesn't reflect anything.
Fresnel reflection simulates plastic surfaces, which reflect better at glancing angles. See the image below to compare fresnel and standard reflections:
The left sphere has 30% reflection level, the right sphere reflects automatically, according to the Fresnel's formula. The reflection level is defined by the angle and by the index of refraction, which is defined in the Refraction section below. There is a lot of information about Fresnel reflection in the Internet, there are tables of refraction indicies for various materials and other useful things that may help to achieve better results.
The chrome effect is useful to make reflective, metallic surfaces. It is usually done by reflecting a special "chrome" texture. See the can images below:
The left can reflects nothing, while the right one reflects a special "environment" texture. Feel the difference!
Blurred reflection may be really useful for rendering brushed metal and similar materials. See the image below:
The left can has sharp reflection, while the right one has blurred. Use the Blur slider to control the level of blur and the Samples parameter to adjust the number of traced rays per sample. The more samples traced, the smoother surface you'll get.
Reflection blur mask helps to make UV-spot surfaces - simply load a grayscale mask having black pixels for glossy areas and white pixels for blurred one, so you can get something like this:
Plane at the left has blurred reflection and no mask, while plane at the right has the same reflection and a mask.
Boxshot comes with a set of built-in materials. Try them and check their parameters to learn how they work that way. The other source of information is Google where you may find enormous amount of information about the reflection process and various parameters affecting it. Lots of commercial rendering engines has the similar parameters, so you may refer to their tutorials, as well.
Finally, feel free to contact us if you feel that something needs to be added to the reflections processing in Boxshot.