3D I – Assignment 1 – Final

And here it is! I present to you, the pinnacle of Assignment I, the Contemporary Urban Crate!
And with it comes a little discussion, of sorts, about the types of maps used and their purpose.

Final version of the crate, with 512p maps.

Diffuse Maps
First off, the Diffuse Maps. This is probably what most think about when they hear “texture”. The diffuse map is pretty much all the basic color information for the object. In this crate it is for example the color information for the wood, showing its grain, branch-marks, separation of planks and the nails.

The things that are good to keep in mind when creating the diffuse map is first of all the layout of the unwrapped UVs. If you don’t keep that in mind the grain (if using this crate as an example) could very well go in different directions on different boards and so on.

Then you need to keep in mind to be very careful with shading on the normal map. When applying light in an engine it would probably look all kinds of wrong with cast shadows from the light source, and separate painted directly on the diffuse map (that are obviously not guaranteed to follow the light in any way). So on diffuse maps the only shading should be self-shading, like a subtle shading in corners or folds, or on occasion shading to accentuate forms.

Also, will the diffuse map have to tile? That could potentially be a big one if you are creating a wall or similar.

Specular Maps
The basic function of a specular map is to determine how shiny an object is, and therefore help one see what kind of material it is made of. This can be very important to help determine what the player Is actually looking at. It determines for example that metal reflects light more than cloth and so on.

On this crate the specular map is actually fairly strong, since aged wood can reflect quite a bit of light from certain angles. The rusty nails were made slightly brighter than the rest as, a bit to my surprise, even rusty nails tend to have a slight metal shine.

The process of creating a specular map is usually a rather simple one. You start by desaturating a copy of the diffuse map, and then simply alter the brightness and contrast of the different parts to relate to the different materials. Anything that is supposed to be shiny should be closer to white, and matte closer to black When creating a specular map for the aged wood this meant that the brighter, smoother surfaces became the shinier ones, just like it should be.

And that is pretty much that.

Normal Maps
The normal map is a very nifty little thing that helps create the illusion of unevenness and depth on a surface. It can give the illusion of indentations and extrusions from the base-model, even though these are simply an illusion created on the materials surface. On this crate this becomes most apparent on a side when it is about to be covered in shade and some parts of the flat surface still manage to catch a bit of light.

A basic rule for when to apply normal maps is to make the model for the silhouette of the object, and anything that then should have depth or extrude, but not break this silhouette, should be created using normal maps.

There are two basic ways to create a normal map (as far as I know at least). The first is to take a copy of the diffuse map, desaturate it, and then alter its values. It is a bit similar to creating a specular map, but instead of being shiny, anything towards the white spectrum will give the illusion to extrude from the rest, and anything reaching for black will become an indentation instead.

The other method is to simply “bake” one from a high-poly model of the object.
Something about the normal maps that can be important to keep in mind is that they are composed of three different layers of information, via the three RGB-channels. Should the normal map come out wrong, it’s therefore usually just best to make another attempt at it rather than to attempt fixing the normal map.

Should one despite this want to fix the normal map it would likely be best to try and fix each channel separately, as to alter the combined picture may create undesired results.

The final Diffuse Map, Specular Map and Normal Map.