The Specular render property uses the same lighting as the default render property but adds further detail to the specular highlight for more realism. The Specular highlight is dependent on the surface angle, light angle and the viewing angle.
The Specular render property lets you add an additional specular texture that defines the specular highlight. This texture determines how light reflects and highlights on the surface of the model.
A Specular Texture defines parts of the surface that might be dirty, scratched or darker. This means that these areas of the surface will react differently to the light source.
|Without Specular Texture||With Specular Texture|
Without a Specular Texture the light reflects off the surface like it's a flat plane. With a Specular Texture the light reflects off the surface based on the defined texture. The Specular Texture defines areas that reflect light and those that do not.
In this example, we can see the worn tyre marks being defined by the texture. These are the more reflective surfaces of the road.
The following properties are available on the Specular render property:
In each Appearance there is a property in the Information Panel called Render Properties.
The Specular render property can be used in a couple of ways. You can use it with a Diffuse Texture or a Diffuse Color and it will define how the light reflects off that surface.
The result will be a surface of either a color or texture with a specular texture defining lighting highlights.
Diffuse Color and Specular Texture
Simple colors can be applied to the surface of a model. A Specular texture can then be added to give that surface defined specular highlights.
Adding a Specular texture to a surface gives it more realism and makes it look like a real surface without defining a Diffuse texture.
Because we haven't defined a Diffuse texture, you have the ability to drive and configure the Diffuse Color. This means you can dynamically control the Appearance whilst maintaining realism.
|Diffuse Color without Specular Texture||Diffuse Color with Specular Texture|
Using a Diffuse Color and not a Diffuse Texture, means that you can configure the color through Rules in DriveWorks. You can configure the color and still use the Specular Texture to make the surface more realistic.
Diffuse Texture and Specular Texture
A Diffuse Texture can also be used with a Specular Texture. The Diffuse Texture can be used instead of Diffuse Color.
A Diffuse Texture can define the detail of a surface. This could be a complex wood grain or complex surface pattern. The Specular Texture will then add realistic light to that surface that matches the diffuse texture.
|Diffuse Texture without Specular Texture||Diffuse Texture with Specular Texture|
The Diffuse Texture helps to define the base outline of the texture. The Specular Texture then adds to that by accurately defining how the light interacts with the surface.
If you compare the Diffuse Color with Specular Texture against the Diffuse Texture with Specular Texture then you should see clear lines defined around each concrete square.
It is recommended that you use a PNG for your Specular Texture. A PNG supports an alpha channel. The alpha channel in the PNG image is used for reflectivity.
If your image has an alpha channel the result will be used to enhance the reflectivity of the model. Transparent areas will result in a low reflectivity and opaque areas will result in the same reflectivity as specified on the Appearance.