CS4620 Modeler: A brief user's manual

This section briefly outlines the use of the framework, from the user's perspective.

Menus

• File
  • Open: selects a file to load. The file must have been produced using the Save As command.
  • Save As: selects a file to save the current model in. It will be stored in the modeler's private binary format.
  • Export: selects a file to save the current model in. It will be stored in the text-based XML format that is compatible with the Ray 2 assignment. Exported files can not be loaded back into the modeler.
• Edit
  • Group selected: Introduces a new transformation node with the selected nodes as children. The new transformation is initialized to the identity. Grouping of objects that are not siblings is not particularly intelligent and may result in some of the objects moving around.
  • Reparent selected: Moves the selected objects so that they are under another transformation. To use this command, first select the nodes to be moved, then choose Reparent selected, then click on the desired parent node.
  • Delete selected: removes the selected nodes from the tree. Be careful, because there is not an Undo command! Note that cameras and lights cannot be deleted.
  • Select: Put the viewports in selection mode, so that clicking selects objects.
  • Translate selected: Put the viewports in translation mode, so that a transformation manipulator is displayed for the selected transformation.
  • Rotate selected: Put the viewports in rotation mode, so that a rotation manipulator is displayed for the selected transformation.
  • Scale selected: Put the viewports in scaling mode, so that a scaling manipulator is displayed for the selected transformation.
• Scene
  • Add Light: Add a new light source to the scene. The new light is always added at the root, and a maximum of eight light sources are allowed.
  • Add Sphere, Add Cube, Add Cylinder: Add a new object to the scene, as a child of the selected transformation node. If the selected node is not a transformation or nothing is selected, the object is added at the root. New objects are always scaled to fill a two-unit cube centered at the origin in local coordinates. Every new object comes with a new transformation node, so that it can be moved around independently of its siblings.

Tree View pane

• Clear selection: Deselect all nodes in the tree. This can also be accomplished by clicking on the background in one of the viewports.

Property pane

• Transformations: text boxes allow editing of the $x$, $y$, and $z$ components of the transformation's translation, rotation, and scaling components.
• Objects: At the top, you can edit the shading model parameters, which are RGB colors for the diffuse and specular components, along with the Phong exponent to control the width of the specular highlight. Below that you can assign a texture to the object, which will modulate the diffuse component of the shading model. The Set button lets you choose an image file; most file formats are supported, but the image width and height must both be powers of 2. The Clear button removes the texture from the object. At the bottom you can set the level of refinement of the mesh used to display the object. Slices is the number of divisions along the object's symmetry axis, and Segments is the number of divisions around the equator. For spline revolutions, there is an Edit button that brings up the spline editor.
• Camera: A text box allows you to change the camera's field of view.
• Light: Text boxes allow you to set the $(x,y,z)$ position and RGB intensity of the light.

Viewport

• Alt/Option-left-drag: orbits around target point in perspective view.
• Alt/Option-right-drag: vertical motion translates along the view direction in perspective view (moves camera closer and farther). To zoom the perspective camera, select it and use the property pane. (Yes, you do need a right mouse button; you will have to plug a two-button mouse into your Mac, or change the UI.)