Fixed Cursor Interface for Touch Screen CAD Precision

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Solution Overview

Problem

Touch input in CAD applications on electronic devices with touch screen displays lacks precision and detail due to limited input types, lack of persistent position tracking, and ambiguity in position designation, making it difficult to interact with detailed and precise elements or points of a model.

Innovation Solution

A fixed cursor input interface is implemented, which superposes a persistent crosshairs cursor on the model workspace and provides a toolbar with icons representing various input types, allowing touch inputs to be mapped to specific actions while maintaining the cursor's position relative to the screen boundaries, enabling 'hover over' functions and precise interactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If touch input is used on touch screen displays, then the interface becomes intuitive and easy to operate, but precision and detail in selecting elements or points of a model deteriorates

Engineering Contradiction:

Improveintuitiveness of touch inputVSAvoidprecision in selecting elements or points

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

A virtual cursor is introduced as an intermediary between the touch input and the model elements. The cursor is displayed at a position offset from the touch point (e.g., at the edge of the screen or in a toolbar area), allowing the user to see exactly which element will be selected before touching. This resolves the contradiction by providing both the ease of touch operation and the precision of knowing exactly which element will be affected.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the entire contact area is registered as touched, then touch input is simple to implement, but ambiguity in position designation increases making precise selection difficult

Engineering Contradiction:

Improvesimplicity of touch input implementationVSAvoidprecision in position designation

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The virtual cursor serves as a mediator that resolves the ambiguity of contact area. Instead of registering the entire finger contact area as the touch point, the system displays the cursor at a specific offset position (such as the nearest edge of the screen or a designated toolbar location). This maintains the simplicity of touch input while eliminating position ambiguity by clearly indicating which specific point will be selected.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of information

If a local magnifier or user interface feature is imposed to show the position under the finger, then position visibility is improved, but the view of the model is blocked causing issues

Engineering Contradiction:

Improvevisibility of position under fingerVSAvoidview of the model

Core Design Contradiction:

Loss of informationVSArea of stationary object

Solution Approach 1:

The position indication function is extracted from the model view area and placed in a separate location such as a toolbar or at the edge of the screen. Instead of overlaying a magnifier that blocks the model view, the cursor is displayed in a dedicated area that does not interfere with the model display. This resolves the contradiction by providing position visibility while preserving the full view of the model.

Inventive Principle:

Principle #2Taking out (Extraction)

4Device complexity

If touch input types are limited to basic gestures, then the input device remains simple, but the number of distinct input types is insufficient for complex CAD actions

Engineering Contradiction:

Improvesimplicity of input deviceVSAvoidnumber of distinct input types

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The virtual cursor enables a single touch input to trigger multiple different actions depending on which element the cursor is positioned over. The same basic touch gesture (tapping, clicking) can select different types of elements (vertices, edges, faces, components) based on cursor position. This resolves the contradiction by providing versatile input capabilities while maintaining the simplicity of the touch device, as the versatility comes from the software interface rather than additional hardware inputs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10073612B1Fixed cursor input interface for a computer aided design application executing on a touch screen device

Publication Date: 2018.09.11 BENTLEY SYSTEMS INC

AI summary

In one embodiment, a technique is provided for using a fixed cursor input interface to interact with a model of a computer aided design (CAD) application on an electronic device having a touch screen display. A view of the model is displayed within a workspace of the CAD application on the touch screen display. A fixed cursor and a toolbar are also displayed on the touch screen display. In response to the touch input within the workspace, a pan or move may be performed within model space to change the view of the model, while the fixed cursor is maintained at a designated position (e.g., the center of the touch screen display). In response to input upon an interface element of the toolbar that represents an input type, an action is performed related to a position in model space superposed by the fixed cursor.