The Pros and Cons of 3D Modeling Paradigms: Direct Modeling and History-based Modeling

The Pros and Cons of

3D Modeling Paradigms:

Direct Modeling and

History-based Modeling

Thank You To Our Sponsor

This webinar will be available afterwards at

www.designworldonline.com & email

Q&A at the end of the presentation

Hashtag for this webinar: #DWwebinar

Before We Start

Moderator Presenters

Barb Schmitz Design World

Brian Thompson PTC

Chad Jackson Lifecycle Insights

Dan Staples Siemens PLM

Software

APPLICATION TO ACTIVITIES

• Designing Products

– Enabling the iteration and exploration of potential design solutions

• Simulating a Product’s Performance

– Abstracting and simplifying a design in preparation for simulation

• Documenting Products

– Creating engineering documentation for downstream application (manufacturing, quality checking, etc.)

• Producing the Product

– Generation of downstream tooling and NC code to manufacture the product

APPLICATIONS IN DIFFERENT STAGES

• Concept Design

– Prior to financial commitment, either in the form of a customer order or formal internal funding

• Detailed Design

– After financial commitment, but prior to design release from engineering

• Manufacturing Prep and Execution

– After design release and before product shipment or delivery

MODELING PARADIGMS: HISTORY-BASED

• Geometry built progressively with features (sketch-based, edge based, etc.)

• Interdependencies built up between features

• Build history of model is preserved in a specific order

• Changes enabled by modifying existing features

MODELING PARADIGMS: DIRECT

• Geometry selected, then manipulated

• Selection or manipulation not constrained by how the geometry was created

• Build history of model not preserved

• Can include parametric modifications

ITS NOT JUST ABOUT 3D

• Sketching Tools

– Constraints enforce properties like parallelism, tangency and the like

– Constraints on an entire set of 2D entities constantly applied during changes

• Drafting Tools

– Properties applied at creation, but not persisted during changes

Concept Design:

Industry Trends and CAD

Development Impacts

Brian Thompson

Vice President, PTC Creo Product Management

February 2014

11

Companies want more concept designs

created in existing time

Companies need Speed and Flexibility

to support the Concept Effort

Concept Design Business Challenges

© 2014 PTC

92% say that they would benefit immensely by exploring

more design alternatives during concept design

Only 16% use 3D modeling tools at this point in the process

* 2011 surveys conducted by PTC: CAD and Complexity (300+ respondents), Concept Design Challenges (200+ respondents),

and 2D and 3D CAD Trends (7,000+ respondents)

12

Teams are wasting time

during this stage recreating data

Teams are duplicating effort

not being able to re-use data

Concept Design Business Challenges

© 2014 PTC

68% say that concept designs typically evolve

by partially or heavily leveraging existing designs

61% say concept drawings/sketches need to be recreated to

support detailed engineering stages

* 2011 surveys conducted by PTC: CAD and Complexity (300+ respondents), Concept Design Challenges (200+ respondents),

and 2D and 3D CAD Trends (7,000+ respondents)

13

Concept Design CAD Implications

Concept Design

Industrial Design 61% say concepts need to

be recreated for detailed design1

• Improved Industrial Design Tools – Better Efficiency – Simpler Paradigm

• 100% Reuse of Freeform surfaces

1 PTC survey of 7,000 manufacturing organizations, October, 2011

14

Concept Design CAD Implications

Concept Design

Industrial Design 2D Engineering

Design

1 PTC survey of 7,000 manufacturing organizations, October, 2011

65% of new concepts

are captured in 2D1

• Purpose Built 2D Design Environment

• Collaborative Connection with 3D

• 100% Reuse of 2D Concepts

• Improved Industrial Design Tools – Better Efficiency – Simpler Paradigm

• 100% Reuse of Freeform surfaces

15

Concept Design CAD Implications

Concept Design

Industrial Design 2D Engineering

Design

3D Engineering

Design 68% leverage existing

designs in new concepts1

1 PTC survey of 7,000 manufacturing organizations, October, 2011

• Purpose Built 2D Design Environment

• Collaborative Connection with 3D

• 100% Reuse of 2D Concepts

• Greater Design Flexibility

• Maintain Existing Design Intent

• 3D Design Paradigm Choice

• Improved Industrial Design Tools – Better Efficiency – Simpler Paradigm

• 100% Reuse of Freeform surfaces

Direct Modeling

A Clarification

• Direct Modeling = No History Tree = No Expensive Regeneration

• Direct interaction techniques that are NOT Direct Modeling

o Face Location Override (A “Move” Feature)

• The move is recorded as a new feature in the feature tree

• As more faces are moved, the tree becomes more and more complex

o Re-direction to Sketch

• The face finds it’s underlying sketch. The underlying sketch is modified and the

history tree re-generated from there down.

• Expensive in large models. Changes limited to original design intent.

Pros and Cons of History-based Modeling

History-based Modeling

Dimension- Driven

Inflexible

Scales poorly on many-featured

parts

Requires pre-planning

Highly Automated

Feature-based

Indirect

More Desirable Less Desirable Less Desirable

History-free (Direct) Modeling

Flexible editing

Feature-less

Direct interaction

Weak dimension-driven

editing

Little design automation

Scales well

More Desirable Less Desirable Less Desirable

Pros and Cons of History-free (Direct) Modeling

Users Don’t Want to Have to Choose! Incorporating the best of both worlds

History-based Modeling

Dimension- Driven

Inflexible

Scales poorly on many-featured

parts

Flexible editing

Feature-less

Direct interaction

Optimal Solution

Weak dimension-driven

editing

Little design automation

Requires pre-planning

Highly Automated

Feature-based

Synchronized Solve

Procedural Features

Driving 3D Dimensions

More… Indirect

More Desirable Less Desirable Less Desirable

Scales well

History-free (Direct) Modeling

History-based Modeling

Single, Seamless System

Surfacing

Castings

Plastic Parts

Stamped Parts

Massive Assemblies

Assembly Productivity

Machined Parts

Straight Brake Sheet Metal

Best Use of Technologies

Optimal Solution

Surfacing

Castings

Plastic Parts

Stamped Parts

Massive Assemblies

Assembly Productivity

Machined Parts

Straight Brake Sheet Metal

Best Use of Technologies

Single, Seamless System

Optimal Solution

Questions?

Barb Schmitz Design World [email protected]

Phone: 440-937-4251

Twitter: @DW_BarbSchmitz

Dan Staples Siemens PLM Software [email protected]

Twitter: @danstaples

Chad Jackson Lifecycle Insights [email protected]

Phone: (512) 284-8080

Twitter: @chadjackson

Brian Thompson PTC [email protected]

Phone: 781-370-5583

Thank You

This webinar will be available at

designworldonline.com & email

Tweet with hashtag #DWwebinar

Connect with Design World

Discuss this on EngineeringExchange.com