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

3,401 views

Published on

Engineering is really all about problem solving. In product design, this means exploring, iterating, changing, testing, and changing again until an optimized solution is found, designed and built. To empower engineers and designers to be able to design truly innovative products, they need tools that are both flexible and powerful.

Parametric, feature-based 3D modeling tools provide engineers with a methodical, orderly and powerfully automated way to create complex models. These tools require engineers to anticipate and define feature constraints, relations and dependencies, which ensure that any design change will be reflected in all downstream geometry. Though powerful, these tools often make edits difficult, especially for those that didn¹t create the original model.

Direct modeling, on the other hand, enables users to take a more flexible, intuitive approach to creating geometry and doesn¹t carry the overhead of history-based dependencies. Users can directly manipulate model geometry without regard to how that geometry was created. To make changes, users simply grab, pull and drag geometry, making direct modeling an easier modeling paradigm to use.

Both approaches have their advantages and disadvantages. Each provides a different kind of value for each stage of development. In this webinar, our speakers will discuss how each modeling paradigm can be used in three phases of product development (concept development, simulation, detailed design).

Published in: Technology

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

  1. 1. The Pros and Cons of 3D Modeling Paradigms: Direct Modeling and History-based Modeling
  2. 2. Thank You To Our Sponsor
  3. 3. Before We Start  This webinar will be available afterwards at www.designworldonline.com & email  Q&A at the end of the presentation  Hashtag for this webinar: #DWwebinar
  4. 4. Moderator Presenters Barb Schmitz Chad Jackson Brian Thompson Dan Staples Design World Lifecycle Insights PTC Siemens PLM Software
  5. 5. 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
  6. 6. 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
  7. 7. 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
  8. 8. 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
  9. 9. 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
  10. 10. Concept Design: Industry Trends and CAD Development Impacts Brian Thompson Vice President, PTC Creo Product Management February 2014
  11. 11. Concept Design Business Challenges Companies want more concept designs created in existing time 92% say that they would benefit immensely by exploring more design alternatives during concept design Companies need Speed and Flexibility to support the Concept Effort 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) © 2014 PTC 11
  12. 12. Concept Design Business Challenges Teams are wasting time during this stage recreating data 61% say concept drawings/sketches need to be recreated to support detailed engineering stages Teams are duplicating effort not being able to re-use data 68% say that concept designs typically evolve by partially or heavily leveraging existing designs * 2011 surveys conducted by PTC: CAD and Complexity (300+ respondents), Concept Design Challenges (200+ respondents), and 2D and 3D CAD Trends (7,000+ respondents) © 2014 PTC 12
  13. 13. Concept Design CAD Implications Concept Design % 61 Design Industrial 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 13
  14. 14. Concept Design CAD Implications Concept Design % Industrial Design • Improved Industrial Design Tools – Better Efficiency – Simpler Paradigm • 100% Reuse of Freeform surfaces 1 65 2D Engineering of new concepts Design are captured in 2D1 • Purpose Built 2D Design Environment • Collaborative Connection with 3D • 100% Reuse of 2D Concepts PTC survey of 7,000 manufacturing organizations, October, 2011 14
  15. 15. Concept Design CAD Implications Concept Design Industrial Design • Improved Industrial Design Tools – Better Efficiency – Simpler Paradigm • 100% Reuse of Freeform surfaces 1 2D Engineering Design • Purpose Built 2D Design Environment • Collaborative Connection with 3D • 100% Reuse of 2D Concepts PTC survey of 7,000 manufacturing organizations, October, 2011 % 68 3D leverage existing Engineering designs in Design new concepts1 • Greater Design Flexibility • Maintain Existing Design Intent • 3D Design Paradigm Choice 15
  16. 16. 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.
  17. 17. Pros and Cons of History-based Modeling History-based Modeling Highly Automated Requires pre-planning DimensionDriven Inflexible Scales poorly on many-featured parts Featurebased Indirect Less Desirable More Desirable Less Desirable
  18. 18. Pros and Cons of History-free (Direct) Modeling History-free (Direct) Modeling Scales well Flexible editing Direct interaction Less Desirable More Desirable Feature-less Little design automation Weak dimension-driven editing Less Desirable
  19. 19. Users Don’t Want to Have to Choose! Incorporating the best of both worlds Optimal Solution History-free (Direct) Modeling History-based Modeling Highly Automated Requires pre-planning DimensionDriven Inflexible Scales poorly on many-featured parts Indirect Less Desirable Featurebased Synchronized Solve Procedural Features Driving 3D Dimensions Scales well Flexible editing Direct interaction Feature-less Little design automation Weak dimension-driven editing More… More Desirable Less Desirable
  20. 20. Best Use of Technologies Single, Seamless System Optimal Solution History-based Modeling Castings Plastic Parts Surfacing Stamped Parts Machined Massive Parts Assemblies Straight Brake Sheet Metal Assembly Productivity
  21. 21. Best Use of Technologies Single, Seamless System Optimal Solution Castings Plastic Parts Surfacing Stamped Parts Machined Massive Parts Assemblies Straight Brake Sheet Metal Assembly Productivity
  22. 22. Questions? Barb Schmitz Chad Jackson Design World Lifecycle Insights bschmitz@wtwhmedia.com Phone: 440-937-4251 Twitter: @DW_BarbSchmitz chad.jackson@lifecycleinsights.com Phone: (512) 284-8080 Twitter: @chadjackson Brian Thompson Dan Staples PTC Siemens PLM Software brthompson@ptc.com Phone: 781-370-5583 dan.staples@siemens.com Twitter: @danstaples
  23. 23. Thank You  This webinar will be available at designworldonline.com & email  Tweet with hashtag #DWwebinar  Connect with Design World  Discuss this on EngineeringExchange.com

×