Before you start ...

You must acquire or create the necessary image files before you can proceed to create your own image-based lighting environment, including:

• HDR panoramic image, used to create lighting maps. Lighting maps add lighting to materials, providing specular and diffuse highlights and reflections.

  The source panorama image used to create the IBL Lighting maps must be an HDR image that shows 360 degrees of a scene around a central point, and 180 degrees vertically (from straight up to straight down). This panorama can be in any of 3 “projections” for a panorama of this coverage:

  • Latitude/ Longitude: similar to a world map, where the sphere is mapped to a 2:1 ratio with the poles at the top and bottom edges.

    

  • Vertical Cross: similar to an unfolded cube, where each face is a rectilinear view of the cardinal directions (up, down, front, back, etc.).

    

  • Spherical: similar to the reflection in a mirrored ball, where the entire scene is warped to fit into a circle within a square image.

    

• You may also start with an existing environment and add a different backdrop or backplate image, depending on the type of environment you are creating.

  A backdrop is a panoramic image of the environment (typically derived from the same file as the lighting maps, but not HDR) which is mapped to the visible environment geometry. The panoramic backdrop image must be in a latitude/longitude (equirectangular "map") format and have an aspect ratio of 2:1. Ideally, it should be at resolution 4096 x 2048. The best file format for this file is PNG (Portable Network Graphics) non-interlaced.

  A backplate image is a regular 2D image, typically showing the location where the lighting maps are centered. The objects in your scene can then be viewed against the backplate with matching reflections and lighting.

How to obtain environment image files

There are several ways to obtain backdrop images and lighting maps:

• Contact the Autodesk Consulting team, who can create the image files you will need for your customized environment.
• Buy pre-built images from an HDRI image vendor such as SpheronVR (http://www.spheron.com) or Dosch (http://www.doschdesign.com).
• Create your own images using specialized 3D software (such as Autodesk Maya, or Autodesk 3DStudio Max) or with a panoramic camera rig and image-stitching software (such as Autodesk Stitcher Unlimited) and HDR-enabled software (such as Adobe Photoshop CS4 Extended http://www.adobe.com, Photomatix Pro http://www.hdrsoft.com, or HDR Shop http://www.hdrshop.com).

Define a custom environment library

Before creating custom environments, a custom library must be defined. This can be a folder on your local machine, or a shared location on a network drive. The user running Showcase must have write permissions to this library location to save a custom environment.

For detailed instructions, see Add a custom environment library.

Create environment maps

After you obtain the environment image file, follow these instructions to generate the IBL maps needed for your own environment in Autodesk Showcase:

1. If the Environments interface is not already visible, press the E key (or select Scene > Environments).
2. Press the Create button at the top of the Environment interface, or choose the menu item Scene > Create Environment...or right-click on an editable environment like Generic or BP Generic, and from the menu that appears, choose Create New Environment.
3. Browse your files and choose an HDR panoramic image meeting the criteria listed in the Before you start...section above.

   After a few moments, the Create Environment dialog will appear and a preview of your environment image will be displayed

   

4. Make adjust the image so that it looks good in the preview using the following tools:
   • Exposure: adjusts the overall brightness of the input HDR scene when creating IBL maps and the background image. The slider has a range of -3 to +3, but values beyond these can be entered numerically. This is useful when the IBL effect is either too dark or too bright.
   • Saturation: sets the overall saturation of the scene. More saturation will result in a more “colored” environment lighting, while less will result in a more “neutral” lighting.
   • Non-Linear Brightness: adjusts both the brightness and saturation of the image at the same time, in a non-linear amount. Useful if the image is extremely dark and contrasted, or light and lacking contrast.
5. Press the Create Environment button to begin the process of creation.

   After the process completes, the newenvironment will be shown in the scene and automatically saved to a temporary directory. The Create Environment dialog remains open for adjustments and recreating the environment with new settings.

More controls and recreating the maps

Press the Show More Controls folder to expose the advanced and individual map controls for the current environment.

• Include in IBL creation.: include this part of the environment map list when creating, or recreating, the environment.
• Output resolution: adjusts the size of each map. The resolution should be chosen by how much detail there is to preserve in the input map.
• Use Tonemap: for the Backdrop (visible) Panorama, combines multiple exposures of the HDR original to create a visually recognizable image.
  NoteTonemapping can produce unusual effects with some very extreme range HDR images. In these cases, simply use the single exposure image automatically generated without this option, or tonemap the image in a separate application.
• Highlight clamp: limits the brightness of highlight pixels by clamping a percentage of them from 0% (no clamping) to 100% (all highlight pixels). This is useful when the scene appears "blown out" or the highlights are not discernable.
• Diffuse Map Quality: changes the convolution of the diffuse map, where higher takes more time to calculate but is more accurate.
• Highlight Map : controls blurriness, where Diffuse is very blurred and Specular is less blurred.