DFTG 1373 Home
Syllabus
Week 1
Course
Introduction
Weeks 14
Thanksgiving
Holiday
Week 16
Final Project Due
Week 8 Notes
Print a rendering of your house to post on the wall.
Save a backup copy of your house scene file after completing materials and before lighting the scene.
Basic lighting
Default lighting
Standard light objects
Mental Ray omni & area lights must use the Mental Ray renderer and are beyond the scope of the class.
Adjust the color of a light
Adjust the brightness of a light
Adjust the hotspot and falloff of a light
Adjust the attenuation of a light
Decay fades the intensity with distance. Inverse square is the most like real-world light, but often fades too quickly in the virtual world.
Include and exclude objects from a light’s effects
Exercise -Light object comparison: Open the file practicelights.max (also available on the I drive), and save to your H drive. Render the Perspective view (use 320 x 240 output size). Save the rendering as default light.jpg.
Place an Omni light in the scene, move it to the correct location, turn shadows on, use Shadow Map shadows, and render . Save the rendering as omni light.jpg.
Do the same with a Target Spot light, a Target Directional light, and a skylight. Use Shadow map shadow type with each light. Turn on Light Tracer when using the Skylight.
Place the five images in a Word document with a caption naming the light used. This is easier if you create a table in Word to place the images and captions in. Print and keep for reference.
Shadows
Types of shadows
- Shadow maps – simple, soft shadows, render quickly
- Area shadows – soft shadows cast from a diffused light source
- Ray-traced shadows – produce exact hard-edged shadows
- Advanced ray-traced shadows – allow smoother edges on raytraced shadows
Apply Shadow types to a light
Raytraced shadows can render very slowly. Increase the Max Quadtree Depth parameter to speed them up.
Mental Ray shadow maps must use the Mental Ray renderer and are beyond the scope of the class.
Note: Use shadow maps when possible to speed rendering time. However, if a light needs to pass through a transparent material, you must use either Raytraced, Advanced Raytraced, or Area shadows; also, transparent shadows must be turned on if using Advanced Raytraced or Area shadows. Shadow map shadows will not go through transparent materials.
Exercise - Shadow type comparison: Open the file globe.max (also available on the I drive), and save to your H drive. Modify the light object and render at 320 x 240 for each of the following settings. Save each rendering as a jpg file, and insert into a Word document with a caption naming each shadow setting. Print and keep for reference.
- Shadow Map shadows, map size 256 (in Shadow Map Params rollout)
- Shadow Map shadows, map size 1024
- Area shadows, Transparent shadows off (in Optimizations rollout)
- Area shadows, Transparent shadows on
- Ray Traced shadows, 2-sided shadows off (in Ray Traced Shadow Params rollout)
- Ray Traced shadows, 2-sided shadows on
- Advanced Ray Traced shadows, Transparent shadows off (in Optimizations rollout)
- Advanced Ray Traced shadows, Transparent shadows on
 Shadow Map Shadows |
 Area Shadows (transparent shadows off) |
 Raytraced Shadows |
 Advanced Raytraced Shadows (transparent shadows on) |
Light Systems for Sunlight
Skylights
The position of a skylight and distance from objects has no effect; light always comes from above.
Using the Light Tracer
The Skylight must use Light Tracer in Advanced Lighting settings. Select Rendering > Advanced Lighting > Light Tracer. Refer to the User Reference for information on the Light Tracer plug-in.
Represent the Sun with a Sunlight system (on Systems panel)
Photometric Light objects, including the Daylight system, require using the Radiosity plug-in and are beyond the scope of the class. Refer to the textbook or User Reference for more information.
Controlling scene exposure
Using Exposure Control
Global Lighting parameters
Select Rendering > Environmnent, choose the Environment tab.
In Global Lighting area, adjust overall scene tint and Brightness level.
The Ambient setting controls the darkness of shadows; a dark gray often works better than black, allowing objects in shadow to be seen better. This also allows Ambient color of materials to show.
Assignments
1. Read Chapter 12 in the Visualization Curriculum Student Workbook and complete the exercises for extra practice.
2. Design a light fixture. Create a light fixture of any kind - ceiling mounted, table lamp, floor lamp, etc. The fixture must have materials applied and include light objects: omni, target, or spot lights. The light fixture should be actual size.
You can use a box to create a quick "room" to test the lights/shadows (since tou can't see them if there is nothing for the light to fall on). Create a box that is roughly the size of a room. Apply the Normal modifier to flip the normals and turn the box inside out. Place the light fixture in the box to see how the light falls on surfaces around the fixture. Delete the box once the light fixture is complete. Group all the objects.
Print a rendering of the light fixture to bring to class. E-mail the max file to me; the light fixtures will be added to the model library.
3. Add sunlight to your building scene. Open your building scene (it should be complete with all materials). Create a ground object (plane, terrain, etc.) for the house to sit on, add a suitable material. You may add walkways and other details as well.
Create a sunlight system; set the location to Plano, Texas, the date to October 1, and time to 2pm. Select the light object (separate from the sunlight compass) and modify the settings as necessary to make it look realistic. Change the Environment (render background) to a sky image. Render a good perspective view to bring to class next week.
4. There is a very good four-part tutorial series at the Area on lighting theory. Go to the Area (area.autodesk.com) and search for Lighting Tutuoral Part 1 to read this series.