The shaders used texture and colour a 3D model play a large part in bringing an object, character or environment to life. There are many things that go into the creation of a surface for a 3D object, using a variety of attributes a texture artist can achieve the variety of complex textures and surfaces. Although there are many of attributes to a shader I will mainly be focusing my discussion around the Colour, Diffuse, Specular and Bump attributes as they could be said to be the most important attributes.
The Colour attribute of a shader is obviously a large part of creating the appropriate surface for a material. The Colour attribute is most often linked to a texture file which has been digitally painted onto the UV with the desired design.
The Diffuse attribute can be said to be the simplest used in texturing. Diffuse shaders allow and object or character to reflect an even amount light across its surface. ‘The Diffuse vale acts like a scaling factor applied to the colour’ (Autodesk. Knowledge Network. Jan 23 2015.) This means that the when the Diffuse value is set to a higher value the actual surface colour will be closer to the colour setting. Put a bit more simply the diffuse can be used to acts as almost a scaling factor for the colours over all intensity by increasing or decreasing the amount of light effecting the object.
High Diffuse Low Diffuse
The Specular attribute is usually used as a highlight on an object or character used in areas that catch most light. Most software allows you to adjust the strength or radiance of the actual highlights as well their colour. This shader is extremely useful in establishing the reflective properties of a surface and the way in which it interacts with light. An example of this would be the difference between and old rusty and new car. A Specular map can allow for the surface of the newer car up appear reflective and glossy while the older rusty car can use very little Specular to communicate the dullness and lack of gloss its surface posses.
Bump maps are able to add a huge amount of detail to a surface making the model appear much more complex then it actually is. Bump maps are used to make surfaces appear bumpy or rough allowing texture artists to add detail to models that does not actually exist on the geometry of the model itself. An example of this may be small cracks in the surface of stone or wrinkles on the face of a character.
Among the attributes I have spoken about there are many more options and methods I did not mention. Although these methods could be said to be used less they still very much have their uses within texturing particular surfaces, below are some brief explanations of these attributes.
Transparency – Effects whether or not an object can be seen through, can be used on glass or crystal like objects.
Incandescence – This is the glow an object has, normally an object would not glow but raising the incandescence can brighten an object all the way up to a white light.
Translucence – Allows light to enter the surface of a material and diffuse off in different directions.
Translucence Depth – Effects how deep light is able to penetrate a translucent surface.
Translucence Focus – Effects the way in which light is scattered in a translucence surface.
The Golf Ball
In texturing a golf ball a variety of attributes would be used in the shader to make the model as accurate as possible while keeping the model from becoming over complex. First a diffuse map would be used to achieve the base colour of the ball, for the sake of simplicity a white base colour could be used. After this a bump map will then be used to create the dimples in the ball, a bump map is used instead of modelling the dimples because the required topology would over complicate the mesh of the model. The specular map will also need to be created to help sell the material of the golf ball. Depending upon how old or new the gold ball needs to be the specular can either make it appear glossy or dull. Below is a quick Golf Ball I put together.
Shaheen, M.S. (June 15th, 2015) Retrieved from http://mshaheenstudio1.blogspot.com.au/2015/06/mshaheen-what-are-most-important.html
Haymes, N.H. (June 14th, 2015) Retrieved from http://nathanhaymes.weebly.com/blog/what-are-the-most-important-attributes-of-a-typical-shader-what-does-each-do-how-does-each-work-and-how-would-they-be-used-to-achieve-a-material-for-the-surface-of-an-old-golf-ball
Martin, A.M. (October 8th, 2015) Retrieved from https://andrewmartinsae.wordpress.com/