Autodesk 507B1-90A211-1301 User Guide - Page 326

and altitude for you. If the sun's mode includes "Intensity", Presenter will also calculate an accurate intensity for the sun based on position, time of year and atmospheric conditions. There are an additional three types of light visible only in photorealistic renders: ■ Projector lights are used to project an image onto surfaces. You can define the file of the image to be projected. ■ Sky simulates the illumination from the sky (but not the direct contribution due to the sun itself). The orientation of your model is defined by north and up directions. The position of the sun is specified as "sun altitude" and "sun azimuth". Whilst the direct contribution of the sun is not included, its location will determine the appearance of the sky hemisphere. If the intensity is left at 0, Presenter will calculate an accurate intensity for you based on the sun's position. ■ A Goniometric light is one which can emit widely varying amounts of light energy in different directions. One goniometric source could behave exactly like a point light, another could behave exactly like a spot light, and a third could look nothing like either of those. A goniometric light gets its intensity distribution function (how much light goes in any one direction) from an industry-standard file. Presenter supports CIE (*.cie), IESNA (*.ies), CIBSE (*.cib) and ILUMDAT (*.ldt) files. NOTE A complete reference manual for all light types is included with the Autodesk Navisworks API (see \API\COM\documentation\shaders.chm). The Autodesk Navisworks API is included with Autodesk Navisworks Manage 2010; it's an optional feature in the installer, and is installed by default into the API subfolder in the Autodesk Navisworks installation folder. Each light type has its own parameters, and the editor for a Point Light is shown here: Point, distant, spot and projector lights have a Location parameter. Distant and spot lights additionally have a To parameter. See "Add and Position Lights" on page 311 for more information. NOTE If the Presenter profile in the Options Editor (see "Presenter Page" on page 436 for more information) is set to Advanced, the dialog box will include a full list of available parameters and allow you to change the type of a light. Point, distant, spot, sky, sun, projector and goniometric lights have the Shadows parameter. See "Shadow Casting" on page 315 for more information. Editing parameters in the dialog will interactively alter the scene with those changes. At any time, clicking the Apply button to apply the parameter edits to the light in the scene. You can save an edited light for use in other scenes by simply dragging it onto the My Lighting user archive. 314 | Chapter 14 Create Photorealistic Visualizations