Adding Support for Specular lighting and point lights

Specular reflection : Specular reflection means that the object is reflecting perfectly, such that the viewer can view the light source reflected from the object. But in the perfect scenario, the user can only see the specular reflection from only one angle, where the incident light angle from the source is equal to the angle to the viewer.

To mitigate this, we use an approximation for specular reflection known as the blinn-phong shading model. The total shading value can be given aswhere N is the normalized normal and H is the normalized half angle between the Light direction and view direction. The alpha is a exponent that represents how smooth an object is. The higher the value of alpha, the sharper the reflection. Specular lights are additive to other lights present in the scene.

Specular highlight: The specular highlight is a bright spot of light where the angle between the incident light and reflected light is the closest. The smoother the material, the sharper the highlight would be. Below you can see the specular light and highlight in action. Here we can see the specular highlight moving when the camera moves. The reason this happens is because of the equation given above, where we are dependent on the half angle between camera to source and light to source.

Below we can see the different variants of shininess. The first is when the exponent is 50 and the second is when the exponent is 10

 

Point Light: Point lights are the approximation to the real world light bulbs in that they emit light in all directions from one point. They are the most used sources of lighting to approximate the real world light sources. In our engine we support only one point light, but there can be multiple of them in one scene. Below we can see point light in action in my scene.