Light Linking using three point lighting:

Light linking is the art of using multiple lights to create the illusion of one. I normally start with a three point lighting scheme (which I will cover later) and then add lights were needed. Linking a light to an object or objects will allow you to control what that light affects. This sounds complex but will make more sense as we get into it later. For this example I will use two tires I created for a car I am working on. (Fig. 1)



NOTE: IT IS IMPORTANT TO NAME ALL LIGHT AND OBJECTS BEFORE YOU START LIGHT LINKING. You can group objects and name them or name all individual objects. But remember to name everything.

Like I stated earlier, I am going to start with a three point lighting scheme. This is where we use three light to initially light the scene (key light, fill light, back light). For more information on three point lighting, go to https://www.3drender.com. That is an excellent source for lighting information.

To start I added one spotlight (key Light) which will be used as my main light source (Fig 2 - 3). This light will be the one to illuminate everything and cast the objects shadows. Then I positioned the light to the angle I wanted. Once the light is positioned, you can change where it points to by pressing the show manipulator button, or T on your keyboard. This will give you a second manipulator, which acts like a target. Just drag this manipulator where you want the light to point to.


After the light is positioned I would adjust it�s attributes and turn on the shadows like explained before. Then test render to see the results. (Fig 4.) You could also play with the decay of the light. With no decay the light lasts forever. By using the various decays (linear, quadratic, and cubic) the light will die out faster but create a softer light. See fig. 5 to compare no decay with a decay turned on.



In comparing figures 4 and 5 you can see figure five is darker but a little bit softer. Figure 5 has a linear decay turned on with an intensity of 10. Experiment to see which lighting fits your needs best.

By looking at the initial render (fig. 4), you can see the backs of the objects, which are facing the viewer, are completely black. Now as in real life, nothing is completely black on the dark side. So we now need to link extra lights to the different objects to backlight them. So we will now create our fill light. The fill light comes in from the opposite side of the object, at a lower intensity that the key light, to lighten the other side of the objects. When using three point lighting, or light linking, the main light should have the highest intensity and cast shadows. Every other light you use should have a lower intensity and not cast shadows. This is what I was talking about when I said we will use multiple lights to create the illusion of one.

Create a new light and position it so it is facing the dark part of the cylinder. (Fig. 6) Then adjust it so the light is somewhat dull; I used .25 for the intensity. We may or may not have to link this light so I would render it to see if it is needed. (Fig. 7)


The render looked nice as is so we will not link any lights yet. You can see in figure 7 that by adding the fill light, we brightened the opposite side of the tires a bit so we can see more detail. Now we can add the last light in the three point lighting scheme and start light linking. The last light is the back light. This is a light coming from behind and above the object/s. This is mainly used just for highlights. I will now add a directional light above and behind the tires (fig. 8). Then I will test render to see if I like it or want to link it. (fig. 9)

NOTE: I USE MY OWN PERSONAL PREFERENCE FOR LIGHTS. IT IS UP TO YOU TO DECIDE WHAT LIGHTS YOU WANT. YOU DO NOT HAVE TO USE SPOT LIGHTS AND DIRECTIONAL LIGHTS LIKE I DO, I JUST FEEL I GET A BETTER RESULT THIS WAY.


Now the three point lighting is done and you can see the effect it has. The directional light gives some mice highlights on the top of the tires and rims, the fill light brightens the back parts just a little, and the key light generates the overall brightness and shadows. Now we can start light linking. Basically, light linking will allow you to add lights and have them affect specific objects. So now we can go through the scene and see what areas are too dark and lighten them up. We can look at figure 10 and see what needs to be lit.