On the Edge: Stream XP, Part 3 of 315 Aug, 2005 By: Russell Brook Cadalyst
Situational inference helps Solid Edge understand what you want to do, thereby speeding up input and capturing your design intent
Last month's article I discussed how process-orientated workflows speed up the design process by automating common tasks. The previous month, I discussed how applied ergonomics reduces fatigue and how the Apprentice Mode helps new and casual users work as productively as their full-time counterparts.
In this concluding part, I will describe how Stream XP uses Solid Edge's situational inference to speed up user input and capture design intent.
Designers spend much of their time inputting data. For many years, people have used CAD systems as electronic drawing boards. Although this method is an improvement over manual drawing boards, many 3D solid modeling applications available today have not gained any significant advancement for data input.
An important concept of Stream XP is situational inference -- streamlining decision management and speeding up user input. Logical inference engines within Solid Edge constantly monitor user input via the cursor position, the mouse movement and the particular task at hand. The goal is to reduce the amount of input the user communicates to the design system to convey design intent. The user can infer quick decisions dynamically.
For example, when placing a dimension between two points, (a simple task in Solid Edge), simply exaggerate the cursor position to either the horizontal or vertical axis, and Solid Edge will show the options available (horizontal, vertical or aligned, etc.) Subsequently, you can place any additional dimensions as a stack or a string with all spacing and formatting controlled by Solid Edge and complying with international standards. Streamlining repetitive tasks such as this one can collectively ease the engineer's job and save a great deal of time.
Solid Edge's situational inference decides on design intent based on geometric input and extent options. Open Profiles assist in solving complex geometric modeling scenarios (less can really mean more); intelligent sketching tools produce accurate lines and arcs from simple freehand sketches. Through the use of intent zones, Solid Edge automatically aligns geometric elements and applies parametric relationships (figure 1). For instance, if you want to place a line at the center of another line, by simply moving the cursor over the center point, the program infers what you want to do. When the line is placed, a parametric relationship locks the line to the midpoint.
Figure 1. Stream XP's situational inference helps the program understand what you want to do and how to make it easier for you to do it.
Situational Inference Example
Solid Edge uses powerful tools to improve user input. For instance, you can simply sketch outlines using freehand cursor movement, and Solid Edge will produce accurate 2D geometry. IntelliSketch infers 13 different parametric snap points (figure 2) and continually hunts for node points (such as end, mid- and center points). It will snap to any condition using intent zones to lock onto geometry, and based on this inferred point, apply a parametric relationship.
The way in which geometry is constructed can also influence how it is constrained. For example, if you draw a rectangle horizontally, the software will connect the corners with the outline being locked into a horizontal and vertical position. Draw a rectangle at any other angle, and the software will connect the corners and place a perpendicular relationship at the corners. This method of working promotes a smooth uninterrupted workflow without the need to create unnecessary construction geometry.
Figure 2. IntelliSketch can capture and apply 13 types of geometric relationships inferred by how the user positions the cursor while drawing. Intent Zones infer users' intentions to place tangent and perpendicular relationships. Smart Dimension infers appropriate dimension formats and orientations from the geometry being dimensioned and the orientation of the cursor with respect to the dimension origins. The Align assembly relationship infers planar or axial alignment from the geometry of the parts being aligned.
Precise selection of information from the graphics window can have a dramatic effect on how users interact with the design system to alleviate frustration and boost productivity.
Solid Edge determines the order in which items are selected using the inferred position of the cursor. As models or drawings become more detailed, Solid Edge has a tool called QuickPick to save the user time and effort (figure 3).
Figure 3. QuickPick works with SmartStep to prevent constant selection rejections and avoid constant view manipulation when multiple selections are relevant.
QuickPick is automatically activated when a user dwells over a region of the design where multiple selections are relevant. Because QuickPick is a part of the active cursor technology employed by Solid Edge, the user does not have to make a conscious effort to turn it on; it is always there to help when necessary. You can use QuickPick for selecting everything from 3D models to elements on 2D drawings to parametric constraints.
To construct a 3D solid in a typical CAD system, you may construct a profile -- a closed shape -- and then project or revolve that shape through space to define the closed volume of the solid. Subsequent features are added to the finished part by defining more closed volumes and adding them to or subtracting them from the existing solid. Solid Edge provides additional capability by inferring closed volumes from open profiles and dynamic extent steps, meaning less input for the user and more decisions undertaken by the program about how to trim and extend the solid (figures 4a and b).
Figure 4. (a) Closed profiles do not infer a closed volume (blue outline defining the rib between the mounting holes). The detail view of adjacent intersections require further work by the design engineer to trim and extend to adjacent faces. (b) Solid Edge open profiles take advantage of inferred decision management (left) where side step and direction are dynamically inferred during feature placement. Solid Edge uses this inferred input to add intelligence to the model and quickly complete the feature (middle and right).
Open profiles offer two advantages over closed profiles. First, with open profiles you can model features in a single operation that require two or more operations to model with closed profiles. Second, open profiles capture an intent that is maintained variationally if the relationship of the open profile to the surrounding geometry changes as a result of later edits. Using a simple profile to infer the boundary of a new solid feature, Solid Edge uses decision management technology to automatically extend the profile to existing adjacent topology.
Solid Edge open profiles let users communicate more of their intentions to the CAD system in less time, and actually produce a more robust model as a result. Inference logic engines monitor user interactions and promote a fuller, more rapid exchange of information between the design system and engineer.
Solid Edge inferred decision management tools let users show the side (one side or symmetrical) and direction (key-in value or dynamic drag) for applying a solid volume from the profile. Real-time feedback alleviates the need to select options via clumsy dialog boxes, providing a more real world feel to modeling with predictable results.
Solid Edge's situational inference engines capture design intent and speed up the design process for engineers. By inferring only the minimum information to describe a feature, designers quickly construct models that are easy to edit.
See you On the Edge next month.
Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!