Current version is LGS 3D 5.0

Version 5.0 improves LGS 3D performance, introduces several new functions requested by LEDAS customers, and enhances the quality of the solutions.

Summary of changes in LGS 3D 5.0 (released in April 2011)

• New API functions LGS3DValidateConstraint and LGS3DValidateContext make it possible to validate one or all constraints without model recalculation
• New algorithm of adaptive calculation of Move Under Constraints step size increased performance of this functionality in two times

• Minimization of number of solving iterations increased LGS 3D performance on inconsistent models by 30%
• DOF computation routine was improved; more pure translational and pure rotational DOFs are detected now
• State CHANGED is set for object if and only if modification of its coordinates/parameters is greater than 1e-12
• Modeling of Cylinder-Torus-Tangency was enhanced and support of orientations was added for this constraint
• Improvement of modeling Circle-Torus-Coincidence constraint (including calculation of orientations from sketch)
• Help points were supported for Sphere-Sphere-Distance constraint. Handling of orientations for this constraint was corrected
• Improvement of naturalness of models with Circle-Cylinder-Distance: more solutions with translations only
• Enhanced processing of constraints in case of parallelism of two lines implied by other constraints
• Help of Legend 3D application was updated

• Non-pure-C DOF computation API functions modified to be pure C
• Heuristic that keeps objects move as a whole was corrected to deal with freeform objects and variables
• Decomposition of model into bi-connected parts was corrected to deal with freeform objects and variables
• Bug of application of transformations to fixed rigid sets was eliminated
• Divergence between set of overdefined constraints and set of overdefined cycles was removed
• Fixed bug of improper processing of fixed freeform parameters in several tangency constraints
• Plane-Cone-Tangency modeling was corrected for case of cone with fixed axis angle
• Incorrect case of modeling of Sphere-Cone-Distance was fixed

Summary of changes in LGS 3D 4.0 (released in October 2010)

• Cone and torus objects in both rigid and deformable modes. New API functions: LGS3DCreateCone, LGS3DCreateTorus, LGS3DCreateAxisAngle, LGS3DCreateMajorRadius, LGS3DCreateMinorRadius.
• Analysis of remaining degrees of freedom that provides the information about all possible translations and rotations of an object or rigid set. A new API function: LGS3DGetDOFs.
• Detection of loops of overdefined constraints. New API functions: GS3DGetOverdefinedCyclesCount, LGS3DGetOverdefinedCycleLength, LGS3DGetOverdefinedCycleConstraint.
• Diagnostics and Move Under Constraints on models with deformable canonic objects.
• Tangency constraints between parametric curves/surfaces and other objects.
• A new analysis on inconsistent models that improves performance three-fold.
• New API function LGS3DSetContextOption to specify options for a particular context. A new context option LGS3D_SCR_PREFIX specifies the prefix for files generated by LGS 3D journaling mechanism.
• Journaling of LGS3DGet* functions. A new context option LGS3D_SCR_EX is used to switching journaling of LGS3DGet* functions on/off.

• Technical and algorithmic optimization increases performance of LGS 3D on large models with thousands constraints by 10-25%.
• A new context option LGS3D_SCR_PATH is used instead of TEMP environment variable to set a path for LGS 3D journaling mechanism to write LGS 3D scripts.

• Behavior of LGS 3D on some cases with line-circle distance and cylinder-circle tangency was fixed.
• Some crashes on Diagnostic functionality were fixed.
• A bug in Legend 3D related to moving objects too far away in Move Under Constraints mode was fixed.
• Inconsistent states are set properly in case of inconsistent specification of planar angle.

Summary of changes in LGS 3D 3.0 (released in April 2010)

• Functionality of freeform objects:
  New API function:
  LGS3DCreateRadius()
• New API constants:
  LGS3D_CONSTRAINT_RADIUS
  LGS3D_OBJECT_FREEFORM
  LGS3D_FREEFORM_FIXED
  LGS3D_FREEFORM_UNFIXED

• Overdefined diagnostic: now all constraints can cause overdefinedness, not only logical constraints.
• Move Under Constraints behavior is improved.
• Help points support is extended to cylinder and sphere objects for the tangency constraint.

• Maintenance of blackbox periods is corrected.
• Now API functions of constraint creation return error in case of a wrong constraint type.
• LGS 3D behavior on problems with planar angles is improved.
• Bug of incorrect API function journaling is fixed.

Summary of changes in LGS 3D 2.0 (released in November 2009)

New

• New API function LGS3DMoveRotateEx() makes it possible to move and rotate geometric objects under constraints with different transformations applied to each of them.
• Mac OS X platform is now supported.
• Custom memory management can now be used for LGS 3D objects.
• Significant run-time performance speed-up (up to ten times).
• Improved diagnostics of over-defined constraints.

• The set of pattern used for decomposition of the initial problem into small subparts has been extended with new patterns to reduce the constraint solving time.

• Several scenarios with unnatural behavior reported by application developers have been fixed.

Summary of changes in LGS 3D 1.5 (released in February 2009)

New

• Performance of MUC functionality is improved in five times while speed-up of other functionalities is about 30%.
• 64-bit platforms are supported.
• Thread-safe code architecture implemented.
• Degrees/radians switching by “angles measure” option in Lege'n'd 3D.

• Lege'n'd 3D has been moved to OpenCASCADE 6.3 version. Now it is based on new version of LEDAS Integration Module 3D.
• LGS3DContext type is declared now as “void*”.

• Fixed crash related to creation of a planar angle without specification of perpendicularity of its arguments and axis.
• Fixed minor bugs in LGS 3D and Lege'n'd 3D code.

Summary of changes in LGS 3D 1.4 (released in May 2008)

New

• New API functions that present functionality of storing/restoring LGS 3D context to/from binary array are introduced:
  LGS3DCreateContextFromBinaryData()
  LGS3DCreateContextFromFile()
  LGS3DGetContextBinaryData()
  LGS3DSaveContextToFile()
• New API functions for working with context tolerances are introduced:
  LGS3DGetLinearTolerance()
  LGS3DGetAngularTolerance()
  LGS3DSetLinearTolerance()
  LGS3DSetAngularTolerance()
• Performance of MUC functionality is significantly improved by implementing new heuristic.
• The Lege'n'd 3D demo application now remembers the last view position of the camera when saving a model.
• The Lege'n'd 3D demo application now can export models to IGES/STEP formats. Also rare formats are removed from the Import menu.

Changed

• In LGS3DGetTransformations() function the type of second argument is changed from LGS3DGeoObject to LGS3DObject.
• The Lege'n'd 3D demo application is switched to the OpenCASCADE 6.2 version.

Fixed

• Fixed cycling bug if rigid set A is a parent of rigid set B and rigid set B is a parent of A.
• Fixed crash in case of a wrong white-box equation given.
• Fixed crashes on some MUC models.
• Improved and extended journaling of API calls.
• Bug of importing some models from IGES format in the Lege'n'd 3D demo application was fixed.
• Transparency mode is now saved/restored along with view position in the Lege'n'd 3D.
• Fixed many minor bugs.

Summary of changes in LGS 3D 1.3 (released in May 2007)

New

• Performance of functionalities Update, MoveUnderConstraints and Diagnostics has been improved twofold.
• Legend3D demo application GUI is improved with selection filter feature, gradient visualization and some other enhancements.

Changed

• API functions LGS3DAddObjectsToRigidSet(), LGS3DCreateRigidSet() now return error codes more correctly.

Fixed

• More natural behavior on Update, MoveUnderConstraints is provided.
• Number of cases with numerical divergence between Windows and Unix platforms is decreased.

Summary of changes in LGS 3D 1.2 (released in January 2007)

New

• Measuring modes to boundaries were extended to all round objects (circles, spheres and cylinders) and to all corresponding distance constraint cases. New measuring mode attribute LGS3D_MEASURE_MODE_CENTRAL_POINT was added for distance and concentricity constraints.
• Performance and success rate were improved on big models.
• New API functions LGS3DGetTopParentRigidSet(), LGS3DGetConstraintParameter(), LGS3DGetWhiteBox(), LGS3DModifyWhiteBox() were added.
• Support of alignment and orientation attributes was improved.

Changed

• Some modification in attribute logic: in this version some attributes in range from 0 to GetAttrCount()-1 may lack. The function GetObjectAttribute() returns LGS3D_BAD_ATTRIBUTE on unused attributes. Some constants for attributes were renamed.
• Planar angles support: in this version it is assumed that the axis is specified to be perpendicular to both arguments of the planar angle because of other constraints in the model.

Fixed

• Updated Legend3D help.
• Provided more natural behavior on Update, MoveUnderConstraints.

Summary of changes in LGS 3D 1.1 (released in May 2006)

New

• Performance and success rate significantly increased.
• Support of round objects (circles, spheres and cylinders) was improved. Most of the distance constraints could be measured to the boundaries or to the centers of round objects.

Fixed

• Fixed several bugs with help-points support.
• MoveUnderConstraints functionality was improved.

Summary of changes in LGS 3D 1.0 (released in December 2005)

New

• Planar angle support was added.
• New API structure LGS3DCallbackUpdate passed to the callback function for obtaining the local coordinate system of the curve/surface appeared.
• Help-points support was significantly improved.
• New API functions LGS3DSetAngleAxis(), LGS3DGetAngleAxis() were added for working with axes of planar angle constraints.
• Diagnostics functionality was improved.

Changed

• Constant LGS3D_RADIUS was replaced by 3 different constants LGS3D_SPHERE_RADIUS, LGS3D_CIRCLE_RADIUS, LGS3D_CYLINDER_RADIUS.
• Useless constant LGS3D_DISTANCE_DEFAULT was removed.

Summary of changes in LGS 3D 0.4b (released in July 2005)

New

• Support for spheres was implemented.
• Variables and white-boxes were added to support engineering constraints functionality.
• Support for swept surfaces was provided.
• Distance measuring mode attributes were added for the "round" objects.
• New API function LGS3DRemoveHelpPoint() and data type LGS3DCharString were added.
• MoveUnderConstraint functionality was expanded to rigid sets.

Changed

• Some API functions, constants and structures were renamed while some constants were removed.

Fixed

• Fixed a large number of bugs in all parts of the solver.

Summary of changes in LGS 3D 0.3b (released in March 2005)

New

• Under- and well-defined diagnostics was implemented and plugged.
• Help-points support was added.
• API was formatted in C-style.
• Spell fixes were provided in API documentation.

Changed

• Obsolete functions LGS3DcreateContextFromBinaryData() and LGS3DGetContextBinaryData() were removed from API.

Fixed

• Fixed a large number of bugs in all parts of the solver.

Summary of changes in LGS 3D 0.2b (released in November 2004)

New

• Overdefined diagnostics functionality was implemented and plugged.
• MoveUnderConstraint functionality was implemented and plugged.
• New alignment attribute LGS3D_ALIGN_KEEP was supported.

Changed

• Some constants were renamed while some others were removed.
• Values of LGS3DObjectType constants were changed according to a new logic of object types.

Fixed

• Compiling was fixed under *nix platforms.
• Fixed a large number of known bugs.