Digital Cinematography

Digital Cinematography -
A simple room lighting scheme - with a light-linking example near the end

Starting with a directional light aimed through the window.
This will be the only light in this scene that will cast shadows (using depth map shadows).

The first render looks like this. Only surfaces lit directly by the window light are visible and everything else is black. We need to add some ambient light.

This is the scene with one ambient light added. Yuk!. It looked even worse when the intensity of the ambient light was at the default "1.0". In this render it was set at "0.25" but still very flat looking.

Delete the ambient light and start building a more interesting lighting scheme which approximates light bouncing around in this scene.

Here two point lights have been added near the floor under the sphere. The intensity on both are still "1.0" but the decay rate has been set to "quadratic". The specularity of each light looks like the bounced lighting from the floor is highlighting the sphere.

A point light is added to the right of the sphere. The color is set to red and the decay rate set to "linear". This simulates the red light which would bounce onto the nearby walls when the bright window-light strikes the sphere. The intensity is exaggerated here a bit to be more apparent.

A point light with a blue tint is added in between the sphere and blue column to simulate light bouncing off the column. Note how it illuminates the left side of the sphere, bringing it out of total darkness as in the previous images.

Also note that there is no specular hilight on the sphere. This is because the "specular" attribute for the blue point light is turned off.

A white point light with a linear decay is placed off-screen to the left. This has the effect of light bouncing off a back wall from the illumination on the floor.

A white point light is placed up high in the room to bring up the overall illumination of the area, bringing a better balance to the other bounce lighting effects in the scene.

The blue column was still dark so a point light was added near the top. This light would have brightened up other areas of the room with an undesired result, so the light was linked exclusively to the column.

To do this, use "window > relationship editors > light linking > light-centric". By linking the light to only the column and nothing else, the light will illuminate only the column in the render.

The resulting scene has one directional light and seven point lights. These eight lights work together to simulate the effect of a single light source coming in the window and bouncing around the room.

Think about ways to light your own scene by making creative use of point lights with decay, color, and linking.

	Starting with a directional light aimed through the window. This will be the only light in this scene that will cast shadows (using depth map shadows).
	The first render looks like this. Only surfaces lit directly by the window light are visible and everything else is black. We need to add some ambient light.
	This is the scene with one ambient light added. Yuk!. It looked even worse when the intensity of the ambient light was at the default "1.0". In this render it was set at "0.25" but still very flat looking. Delete the ambient light and start building a more interesting lighting scheme which approximates light bouncing around in this scene.
	Here two point lights have been added near the floor under the sphere. The intensity on both are still "1.0" but the decay rate has been set to "quadratic". The specularity of each light looks like the bounced lighting from the floor is highlighting the sphere.
	A point light is added to the right of the sphere. The color is set to red and the decay rate set to "linear". This simulates the red light which would bounce onto the nearby walls when the bright window-light strikes the sphere. The intensity is exaggerated here a bit to be more apparent.
	A point light with a blue tint is added in between the sphere and blue column to simulate light bouncing off the column. Note how it illuminates the left side of the sphere, bringing it out of total darkness as in the previous images. Also note that there is no specular hilight on the sphere. This is because the "specular" attribute for the blue point light is turned off.
	A white point light with a linear decay is placed off-screen to the left. This has the effect of light bouncing off a back wall from the illumination on the floor.
	A white point light is placed up high in the room to bring up the overall illumination of the area, bringing a better balance to the other bounce lighting effects in the scene.
	The blue column was still dark so a point light was added near the top. This light would have brightened up other areas of the room with an undesired result, so the light was linked exclusively to the column. To do this, use "window > relationship editors > light linking > light-centric". By linking the light to only the column and nothing else, the light will illuminate only the column in the render.
	The resulting scene has one directional light and seven point lights. These eight lights work together to simulate the effect of a single light source coming in the window and bouncing around the room. Think about ways to light your own scene by making creative use of point lights with decay, color, and linking.