3d Lighting Setups: 3 Point Lighting
When I began writing this tutorial I found it difficult to separate lighting techniques from color theory and frame composition. I had to decide what I thought would be the most enlightening (sorry couldn't help myself) approach. So I have decided to make this Part One of many tutorials to follow. This tutorial will focus on 3 point lighting setup. I have intentionally set this up as a grayscale image. This way the lighting will be the only focus. A tutorial on additive color theory will follow shortly. (and yes I do know that white light contains the entire spectrum of color but more on that later)
Every 3d artist and enthusiast should be well versed in how to create a 3 point lighting setup. 3 point lighting setups are the bread and butter of set lighting. The benefit of 3 point lighting is that it paints beautiful 3 dimensional light on the subject. It is also a very flexible lighting set up. For example, you can create 2, 3 or more 3 point setups in a single scene.
This is an example of Max default viewport lights. Here only 1 light is used. Notice how washed out the character looks. This is ugly, very cg, and doesn't do anything to compliment the model.
This another example of Max default viewport lights. This time there are 2 lights used. Notice the stark contrast between light and shadow. This is better then the one light option but it still leaves a lot of room for improvement.
Key Light Placement
The Key Light is the primary light in your scene.
Top view: The Key light is placed next to the camera. How far or how close to the camera is up to you. Generally, you will want to place the Key Light at an approximately 35-45 degree angle to the subject.
Side view: The Key light is generally placed at a 45 degree angle from the subject. Use this as a rule of thumb, this is by no means written in stone. The angle of your Key light is determined by what kind of mood that you want the scene to have.
General Parameters roll out
- Type: Target Spot, Target Direct, Free Spot, Free Direct, Omni
- "On" toggle: Turns a light off and on.
- "Shadows" toggle: Turns shadows off and on.
- Color swatch: This allows you to change the color or tint of the light. I have all of the lights in this tutorial set to white. Color helps set the mood of the scene.
- "Exclude" button: This gives you the option of what objects will be excluded from the light.
- You can also choose to exclude an object from just illumination or just casting shadows. More on
- "R.G.B and HSV": Another option for adjusting the color or tint of the light.
- "Multiplier": This sets the intensity of the light. A setting of 0 is no light. An interesting effect occurs when you set this to a number below zero and the light will subtract light from the scene.
Shadow Map Parameters roll out
- "Bias": nudges shadow toward or away from the object casting it.
- "Size": A shadow map is actually a bitmap that is rendered. If the map size is too low the shadow may appear to be grainy and animated the shadow tends to crawl.
- "Sample Range": This softens the edge of the shadow similar to a guassian blur.
- "Absolute Map Bias": Similar to the above bias setting but on a global scale.
The settings I used for the Key Light
- Light Type: Target Spot Light
- Shadows turned on
- White color (Normally I would slightly tint the light but for the purpose of this tutorial I
left this at white so the image remained grayscale.)
- Multiplier: 0.9. (You will want to adjust this number based on the environmental needs of your
image especially if you have chosen to tint the light. The more saturated the color the less intense the light becomes.)
- Shadow map parameters:
- Bias: 2.0 (I didn't like the tiny shadow cast on my characters right deltoid muscle by adjusting this number slightly it nudged the shadow just enough to get rid of it.
- Size: 1024
- Sample Range: 12 (I thought the shadow was much too sharp at the default setting of "4". A setting of "12" added a nice guassian type blur to the shadow edge.)
- Absolute Map Bias: left unchecked
Fill Light Placement
The Fill Light softens the shadows cast by the Key Light and adds some additional illumination to the subject.
Top View: Fill Light Placement
Place the Fill Light at a 90 degree angle from the Key Light.
Front View: Fill Light Placement
The Fill Light is generally placed slightly higher or lower then the Key Light. Here I chose to place it on the same elevation as the Key Light.
The Fill Light settings that I used
Back Light/Rim Light Placement
Back Light, Rim Light, Hair Light....whatever you choose to call it. This is the light you would use to create a rim of light or a halo effect around the edges of your subject. A Back Light is used to separate the subject from it's background and to add a 3rd dimension to the subject.
Top View: Back Light Placement
The Back Light is placed directly opposite the camera and behind the subject.
Side View: Back Light Placement
The Back Light is pointed at a sharp angle towards the subject. Be careful here, If you place the light too low or if the angle is set too close to 90 degrees the light will spill over onto the face or frontal areas of the subject.
The settings I used
- Type: Target Spot
- Shadows: On
- The rest of the settings I left at default.
This is a good time to discuss attenuation. When I set up the Back light I had a tremendous amount of illumination on the top of my character's feet (see the image on the left). When the other lights of the scene were added the problem grew worse. In fact, the top of the feet were blindingly white. I needed some way to tone down or exclude the feet from the Back Light without excluding the rest of his body. Light attenuation was the answer.
In real life the illumination from a light source diminishes over distance. In 3d, the illumination of a light will continue through infinity unless modified by the user. This is attenuation. Basically, you set the light parameters so that it diminishes(falloff)over distance.
In the example to the left, you can see how attentuation works. The light starts at zero as it leaves the light source and gradually grows brighter until it reaches it's maximum intensity. Once the maximum intensity has been reached, (note the area between "end" designated by a blue ring and "start" designated by the light tan ring, in the image to the left,) the light gradually dims back to zero.
Attenuation Parameters Roll out
- Near Attenuation(dim to bright)
- Start: sets where the illumination begins
- End: Maximum intensity start point. Far Attenuation(bright to dim)
- Start: Maximum intensity end point.
- End: Sets where the light dims to zero Decay is another method of attenuation. It can be used alone or with the above attenuation settings.
- Type: Inverse-the light's strength decays but not as soon or as powerfully as inverse square
- Inverse Square - the real world decay of light. This tends to make things too dark.
- Start This adjusts where the decay begins
- Show: toggle for a visual helper for the decay settings
I used two other lights in this scene. A Background Light and a Bounce/Radiosity light. The Background Light
was added to soften the areas of the background and the floor that the Key Light doesn't illuminate. The Bounce/Radiosity Light was added to give a suggestion of radiosity to the scene. However, it is possible to skip this light through creative placement of the Fill Light. I use a separate Bounce Light because I feel it gives me precise control over the illumination.
I placed the Bounce Light opposite of the Key Light. Since the Key Light is the strongest light source in the scene, I want the light to appear as if it's bouncing off the floor and walls and traveling back to dimly illuminate the character.
The Background Light was placed fairly parallel to the Key Light and angled slightly to the left. The idea is to illuminate the areas in the frame that the Key Light doesn't cover. This also gives me enough room to adjust the hotspot and falloff parameters of both lights.
Here you can see that the Bounce light is placed below the ground plane, fairly opposite the placement of the Key Light.
The Background Light was placed at a sharper downward angle then the Key Light. This was done so that the Background Light's hotspot would shine directly on the darkest part of the background. I adjusted the falloff and hotspot parameters of the Background and Key Light in order to get a nice glow in the area where the two lights meet.
What is Falloff?
Falloff is the area where the light fades from its brightest to zero. The image to the left demonstrates where the hotspot and falloff areas are in each light(Background and Key Lights). The blend area is the area where the falloff from the Background light and the falloff from the Key Light combine to create even illumination.
Spotlight Parameters Roll Out
- Light Cone
- Show Cone: toggle this to make the lights cone visible even when it's not selected.
- Overshoot: causes the light to radiate beyond the fall off area. Shadows are still cast with in the fall off area.
- Hot Spot: The center circular area of the spotlight. The brightest/hottest part of the light.
- Fall Off: The outer circular area of the spotlight. Light fades to zero as it reaches the outer edge.
- Circle: Creates a circular beam of light.
- Rectangle: Creates a rectangular beam of light.
One final thing...clean up the image by excluding the background from some of the lights.
First go to the "General Parameters" roll out and click on the "Exclude" button. To exclude objects from a light, its just a matter of selecting the object in the scene objects window, clicking the double arrow button and the object then appears in the exclude window.
Another option you have is to select the "include" toggle. This will include any object that you have transferred over.
In addition to the Include/Exclude toggles, you can choose to exclude/include an object from just illumination or just casting shadows.
I excluded the background from the Fill light and Back Light.
Well that pretty much wraps it up for 3 point lighting. In the next installment I will cover the topics of Narrow Lighting, Eye Lights, Wall Lighting, and Pools of Light. Hopefully you will find this tutorial helpful.