LESSON Austin Community College | Visual Communication Design ARTV-1445 3D Modeling & Rendering 1 Basic Lighting 05 NEW SKILLS/CONCEPTS: Becoming familiar with the light types in 3ds max Understands the differences between light types Understanding and being able to use the appropriate of a light’s intensity, color, and shadow type for a particular situation Understanding the basics of “modeling with light” OBJECTIVES: Using Standard Light types to… Part I: Light the scene based on the sources of light and the mood you are trying to create. Include fill lights to represent the bounced light in the room. Part II: Using the technique of “3 point lighting”, light one (3D) object in the scene with additional light to boost the light and draw the viewer’s focus to that object. Final Scene: Demonstrate understanding of the standard lights types Scene is lit with appropriate “key to fill” ratio (low = light scene, high = dark scene) Scene is lit with enough “bounced light” to help light the darkest areas Each light is named descriptively – I.E. lamp-omni, lamp-spot, key, fill, back, etc. Scene file is saved in student’s folder and instructor’s folder for critique Save Rendered .jpg in student’s folder and instructor’s folder for critique READING ASSIGNMENT: Visual Quickstart Guide 3D S Max 6 for Windows Chap. 11; pp. 335 – 361 (emphasis on pp. 335 343) The Art of 3D Computer Animation & Imaging Chapter 8, Lighting DEFINITIONS: 1. LIGHTS Omni Light (omni-directional, point) – radiates light in all directions. Examples: candle light, light bulb, star, firefly Directional Light (sun, infinite, direct) – radiates with parallel rays of light. Sets a single vector for all its illumination and hits every object from the same angle, no matter where the object is located. All of the shadows cast by a distant light are cast in the same direction and are Basic Lighting Page 1 of 4 Austin Community College | Visual Communication Design ARTV-1445 3D Modeling & Rendering 1 orthogonal projections of each object’s shape. In 3ds max can be targeted and use a cone of illumination. Examples: sun, moon Spotlight - A spotlight casts light from a point in a cone shape and only in one specific direction. You can also link a "target” to the light so that the light is always oriented toward the position of the target. Spotlights have a variable –angle cone and a light fall-off factor (decay) Examples: headlight, flashlight, movie projectors, lamp shades. Skylight - The Skylight light models daylight. It is meant for use with the Light Tracer. You can set the color of the sky or assign it a map. The sky is modeled as a dome above the scene. This light is works in a similar fashion to the Area Lights in other programs. You can render without using Light Tracer but the image is grainy unless the rays are set to a high number (it takes a very long time to render) Ambient Light - (also called global ambience – EVIL… makes your 3D scene FLAT)-- In real life, ambient light is widely distributed, “indirect” light that has bounced off objects in your scene. Ambient light illuminates even the areas not directly lit by another light source. In 3D graphics, the ambient light means an amount of flat, evenly distributed light added to objects in a scene, making the objects visible even when no light source illuminates them. In 3ds max, the ambient light default setting is “0” Basic Components of a Light Source: Position and Orientation Color and Intensity – simulated lights can be any color. The color of lights is based on the additive color model (RGB or HSB). Intensity or brightness can be controlled independently of the color BUT since they influence each other, almost any change in color affects the lights intensity Attenuation – the effect of light dimming over a distance; use this to reduce the space lit by that source Beam Angle – defines the diameter of the beam of light and also the surface area covered by the light. Glow and Cone of Light – glow is a circle of light that forms around a light source. 2. SHADOWS Types of Shadows: There are 4 types of shadows that a scanline renderer can project from a light. In this exercise we will only concern ourselves with the Default Shadow Map type. a. Shadow maps (Depth Mapped) – bitmaps that are projected from light Shadow map shadows use a pre-calculated depth map to determine where shadows will be rendered. A depth map is an array of numbers representing distances to the nearest shadow-casting object found in each direction. It makes the light appear to be blocked by other objects, without the renderer needing to check the geometry of the scene while rendering each point. Shadow maps don't show the color cast by transparent or translucent objects. On the other hand, shadow maps can have soft-edged shadows, which ray-traced shadows cannot. To get a nice shadow, you usually need to increase the shadow map size. b. Raytraced Shadow Basic Lighting Page 2 of 4 Austin Community College | Visual Communication Design ARTV-1445 3D Modeling & Rendering 1 3. Three-Point Lighting One of the most popular and attractive ways to illuminate any subject is with a classic Hollywood lighting scheme called three-point lighting. This makes it easy to model your subject with light. One of the main goals of 3 point lighting is modeling with light. To model with light is to illuminate a subject so that your 2 dimensional output shows the subject’s full three-dimensional form. Key light - creates the subject’s main illumination and defines the dominant angle of the lighting. The key light is usually brighter than any other light illuminating the subject and is usually the light that casts the darkest, most visible shadows in your scene. o Placed 10 to 50 degrees to the right or left of the camera. o Placed above the camera o Strongest light o Dominant shadow Fill light - softens and extends the illumination provided by the key light and makes more of the subject visible. The fill light can simulate the effect of reflected light or of secondary light sources in the scene. o Opposite side of subject from key relative to camera about 10 to 60 degrees from camera o Shouldn’t be any lower than camera (eye level) and up to about o 15 degrees about camera Should overlap key Backlight/ Rim - creates a “defining edge” to help visually separate the subject from the background. With this light, you want to make certain that the objects are not totally lost in the shadows o Helps to separate the subject from the background. Gives the scene depth by illuminating the back of a subject, giving a subtle glowing edge which helps create definition. PRACTICE: Before you begin this exercise, read through the Chapter on Lights in the Quickstart book and experiment with the different lights to see how they work and their effects. If you want to see shadows cast, you will have to select the Light, go to the General Parameters in the Modify menu and turn Shadows on. To easily access the Lights you have put in the scene, go to Tools/Light Lister. When you feel comfortable using the difference types of lights you may go to the exercise. Before you begin this exercise, open your “Pirate Scene” file and practice lighting the scene with the a specific mood. Basic Lighting Page 3 of 4 Austin Community College | Visual Communication Design ARTV-1445 3D Modeling & Rendering 1 EXERCISE: You will light this scene twice. Once for the environment lighting, and once with environment lighting and 3-point lighting. Keep your lights on their own layer. Pick a mood and try to push that idea. Pick an object from your scene and boost the light on this object using 3 point lighting. Part I: 1. Open the “AmmoRoom_Start.max” scene file. 2. FYI: You’ll have better luck if you use Targeted Spot, Targeted Direct &/or Omni lights only. 3. Look in all the views (except the camera view). 4. In the first section of the exercise, light your scene with a specific mood, and as if the light is coming from the implied light sources: window, door, lamp. 5. You will need additional lights to create the illusion of bounced light. All these bounced lights should give DIFFUSED shadows. All these bounced lights should give DIFFUSED shadows. To do this, set the Shadow Map Parameters “Sample Range” to be somewhere around [20.0-40.0] (a higher number create more diffused/blurry shadow) 6. Name your lights, such as Direct_Sun (or window) and Spot_Overhead. 7. When you are happy with the look of this scene, Render and Save the file. Save the scene file. They should be named “Name_Lighting-Environment” PART II: 8. Pick an object in the scene. Choose which camera you want to work with. You will light your chosen object using 3-Point Lighting to boost the light and draw the viewers attention to that object. Set your main light (called KEY) to the side of the camera that the main light in the room is coming from, but in front of the object, relative to the camera. This light should be the brightest light in the 3-Point Light Kit This light should probably cast specular shadows 9. Render your view. Determine where you need the fill(s) light to be able to see the objects better. You’ll want them to remain shadowed, but still be visible (this is what we mean by “modeling with light”). 10. Create a second light and call it FILL (it fills in the shadow area). It should be quite a bit less intense than the key. (Together they should add up to no more than 1.3). This light should pick up a little of the color from the objects around it, so you’d want to tint it with a bit of whatever color you use on your surfaces. These lights should be DIFFUSED so set the Shadow Map Parameters “Sample Range” to be somewhere around [20.0-40.0] (a higher number create more diffused/blurry shadow) 11. Render the Camera View. What is still too dark? Do the sides of any of the objects disappear into the shadow area? Is there enough light on the top of the objects? Often you will need more than one “fill” to represent the bounce lights in the scene. 12. Add “rim” lights behind the object relative to the camera. You may want to call it RIM or BACK. This light does not cast shadows. Nor does it affect the specularity of your objects. It can be what ever brightness you need but you do not want it to look like there is a light back Basic Lighting Page 4 of 4 Austin Community College | Visual Communication Design ARTV-1445 3D Modeling & Rendering 1 You can use “Attenuation” to limit where the light falls, but this may not give you exactly what you want. Instead, you may want to use the EXCLUDE/INCLUDE option. You might wish to EXCLUDE the wall or floor, or just INCLUDE the object you are lighting. 13. Continue to tweak your lights until you are happy with the results. 14. Be able to explain to me the differences you see between the two approaches to lighting. 15. Save the image as “Name_Lighting-3pt.jpg”. Save the scene file as “Name_Lighting-3pt.max”. 16. Save all 4 files into your folder on your computer and (through the Network Places) into the instructor’s “Ready For Review” folder. Basic Lighting Page 5 of 4