Modifying The Scene Background

You can customize a scene background to have a color, 2D Image, 3D Environment, or a 3D Skybox. You can customize the background by two methods:

• By dragging and dropping a color, 2D texture, or 3D Environment onto it from one of the available catalogs.
• By using the Background properties and directly specifying the appropriate method.

Background Dialog Box Options

The background dialog box controls the settings for customizing the scene background. This can be accessed by right-clicking in the scene background and select Background.

• Solid Color.  Select this option to specify a homogenous color for the scene background.
  Top/Bottom Color.  Select a background color from the standard palette. Select a top and bottom color to define a gradient.
  More Colors.  Select this option to display an expanded color palette or define a custom color.
  Pattern. Select the desired pattern affect between the top and bottom colors defined.
  Use Background Image in Reflection From. Select this option to use an image set in the 2D Texture, 3D Environment, or 3D Skybox in real-time reflections on surfaces and parts while using a color background. This allow the ability to set a specific background while achieving realistic reflections on objects in the scene.‍
• 2D Image Texture.  Select this option to specify a graphic image for the scene background.‍
• Image.  Use the following options to define an image file to be used for the scene background.
  Image File.  In this field, enter the name of the graphic image file to be used or select Browse to locate/select the file.
  Stretch image to fill page or scene.  Select this option to specify that the selected image file should fill the entire background of the scene.  The image is automatically expanded, as necessary.
  Fixed Aspect and Location  Select this option to maintain the height of the selected image proportional to its width and position it to a desired location using the available radio buttons to locate the image. This option reduces distortion in photos and other realistic images.
  Repeat image to fill page or scene.  Select this option to create multiple copies, as necessary, of the selected image file to fill the entire background of the scene.
  Number of horizontal repeats.  If the previous option is selected, use this field to specify the number of times the selected image is repeated horizontally.  The aspect ratio is preserved and the image is repeated vertically to fill the scene.
  Exposure.  The exposure of the image may be adjusted.  Higher numbers give brighter results.  Negative numbers give darker results.
  Smooth image.  Select this option to smooth blockiness in the selected image file, resulting from adapting a small image to fit a scene background.‍
• 3D Environment.  A background where the specified image is projected onto a sphere surrounding the scene.  The sphere is of infinite size.  This is highly useful for realistic reflections and global illumination.  Because of the massive area covered by the image, the image itself may appear at a low quality.  Frequently, the environment will not be visible directly- but only in reflections and lighting. Note: These will display as 3D in OpenGL and Advance OpenGL/Direct 3D Modes rendering modes only.
  
  High Dynamic Range Images (HDRI - File extension = .hdr or .exr) are commonly used in the 3D Environments. HDRIs are ideal for use in combination with GI to recreate very natural and realistic lighting situations. HDRIs also have a big impact on the realism of reflections because they can produce reflections on objects that are much brighter than reflections caused by normal textures.
  
  In short, HDRIs are images with a very high brightness range, much higher than normal RGB images, which are limited to a brightness range of 8 bits (256 variations) per color.
  
  Standard RGB images have the limitation of the brightest possible color being a 255/255/255 white. If you use such an image in combination with GI to illuminate a scene, even the brightest white won’t be bright enough to simulate a real lighting situation. The resulting renderings often look flat and lack contrast. That’s because in reality the difference between a dark light (e.g. candle flame) and a bright light (e.g. sun) is too big to be represented within an 8-bit RGB image.
  
  However, using a HDRI, the sun could have a brightness value of, say, 6000% that is taken into account by the GI algorithm and when rendering reflections. This results in beautifully and realistically illuminated scenes. There is a sample set of HDR images (.hdr) in the IronCAD Image folder.‍
• Mapping Type.  The mapping type sets the mapping of the 3D image used in the environment. Ideally you would use this option to maintain the environment image based on its current mapping type. Normally you would not change the image mapping type to a different type unless you are attempting to obtain a desired look.
  Spherical.  A full 360 x 360 degree view of the scene is given in a rectangular latitude-longitude format.
  Angular.  A full 360 x 360 degree view of the scene is given in a circular format with the exterior representing the backwards direction.
  Up Direction.  The global direction to be treated as the environment up (+Y) direction.  Typically this will be +Z (0,0,1).
  Rotation.  A rotation about the Up vector to offset the environment
  Exposure.  The exposure of the image may be adjusted.  Higher numbers give brighter results.  Negative numbers give darker results.
  Smooth image.  Select this option to smooth blockiness in the selected image file, resulting from adapting a small image to fit a scene background.‍
• 3D Skybox.  A background where the specified 6 images are projected onto a box surrounding the scene. This is highly useful for realistic reflections and real-time performance.  These images are very similar to 3D Environments but have excellent quality for real-time display as well as optimal performance since they are usually smaller in size than 3D Environments. Note: 3D Skybox images will not appear in realistic rendering results.
  Choose Predefined Skybox. Select this option to select a predefined skybox example.
  Custom. Select a custom image file to be used for the skybox.

Note: You can edit each type without activating the setting. Select on the name to edit the settings. Select on the Radio Button to activate it as the desired background option.

To Assign A Color/ Texture To The Scene Background Using The Drag-And-Drop Method:

1. Display the contents of the catalog containing the desired color, 2D texture, or 3D Environment.
2. Drag the catalog item into the scene and drop it anywhere on the scene background. Note: To use the 3D Environment, the scene has to be set to 3D Environment in the properties first or you need to toggle to this setting after drop.