Geometry_Editor

The NiCE Geometry Editor provides users of NiCEClient a method for viewing and editing application-specific input data in the form of 3D volume meshes. Editing is performed by means of constructive solid geometry, as is used in many CAD and drafting tools. The Geometry Editor integrates with NiCE to enable users to build geometry data inside the NiCEClient window, as well as to generate output formats to be served as input data for processes launched with NiCECore.

• Requirements
  • User Interface
  • Geometry Engine
• Graphical User Interface
  • Viewport Panel
  • Object List Panel
  • Transform Panel
  • Mini-Axis Widget

Requirements

User Interface

The user must be able to perform the following from the Geometry Editor's interface.

• Add shapes from a predefined list to the viewport
  • Sphere, cube, cylinder, imported custom meshes, etc.
• Apply set operations to two or more objects
  • Union, intersection, compliment
• Edit each shape's matrix transformations
  • Position, size, scale, rotation, shear
• Select groups of objects as well as individual primitive shapes
  • Once selected, the user may delete, duplicate, or reorder its role in the CSG tree.
• Optionally rename instances of primitives and groups

Geometry Engine

In order to integrate with NiCECore, NiCEClient, and third party applications, the geometry engine must have the following capability.

• Initialize, import, and modify a CSG tree
• Generate a triangle surface mesh for the jMonkeyEngine Mesh format in order to display an interactive preview for the user in the Geometry Editor's viewport
• Generate a tetrahedral volume mesh to be used by a third party application
• Build a NiCEDataStructure with CSG tree and program state data, including all information required to persist and restore a Geometry Editor session
• Export to standard and application-specific geometry and volume mesh formats
  • BREP, etc.

Graphical User Interface

The Geometry Editor GUI is opened from within the NiCEClient environment. Within this environment are three dockable panels—the Viewport panel, the Object List panel, and the Transform panel. Each of these are used to manipulate the CSG tree, i.e. create shapes, relate them with set operations, and edit their transformation matrix.

Viewport Panel

A variable-quality rendering of the CSG tree is displayed in the Viewport panel, along with a Mini-Axis Widget for determining the orientation of the virtual camera. With the mouse, the user can pan and rotate the camera's perspective and select certain types of primitives and groups. Right-clicking will display a context menu with additional features for quick access.

Object List Panel

The Object List panel features a representation of the current CSG tree as a SWT Tree or JFace TreeViewer. Leaf nodes in this tree list correspond to primitives, while parent branches represent set operations applied to their child nodes.

Transform Panel

Mini-Axis Widget

"I hate meshes. I cannot believe how hard this is. Geometry is hard."

—David Baraff, Senior Research Scientist, Pixar Animation Studios