1.6.1 Alpha preview

Today we made a 1.6.1 alpha build to offer users some preview on the latest features we plan to launch.

We made a big rewrite on NaroCAD and added: integrated a solver algorithm, implemented the Sketch concept and 2D tools that use the Sketch, reimplemented Extrude to work with sketch shapes, added 2D dragging handles that work on the current sketch. A final updater version was also included in this build.

A sample movie that demonstrates lines drawn having a perpendicular constraint on them. Demonstrates solver behavior when a point is dragged:



Another sample that demonstrates drawing a rectangle (that is built from lines with constraints) and also a circle center connected to one rectangle corner:



Download NaroCAD 1.6.1 Alpha from here.

Rectangle as Constrained Lines

Rectangle implementation is defined right now as constrained based four lines shapes.
This implementation shows lively how constrains work and will be a good test case to them too.
So look here for details:

Sketch Constraint Document Apply

Sketch shapes that are referred by constraints if changed on commit they will trigger automatically the solver. This also implied a code refactor that exposes which shapes are lively changed in document. Also, based on Sami's work that when you press Sketch button, the sketch shapes buttons are enabled, the code was made better both as quality and how behaves making it more consistent and easy to use. The Sketch Constraints button was moved to the Sketch Section so will be easily accessible to access shapes.

2D shapes dragging handles

Modified line dragging handles so that the user can drag 2D shapes only in their Sketch plane. Implemented also a new type of 2D rectangle dragging handles used for 2D shapes. Will apply these modifications also at the other 2D shapes.

SketchSolve Action Preview

A full solver for sketch shapes (based on SketchSolve code) is right now in preview state in an easy to use action. So this video explains it how it works and how to use it:

2D Sketching tools

Worked at porting the 2D drawing tools to use the Sketch concept. Implemented the Arc CSE (center, start, end), Arc SER (start, end, radius), Ellipse tools including animations. Fixed the line and circle tools, improved the sketch launch/close functionality.

SketchSolve NaroCAD Infrastructure Explained

SketchSolve is a 2D Sketch Constraint Solver and NaroCAD is a 3D based designer.
SketchSolve have mostly a dynamic programming solution optimizer that will apply the constraints using a big dispatcher to compute the errors that may happen in applying the constraints.
From NaroCAD standpoint challenges are at two levels: sketch shapes need to be sketch oriented, so by design all shapes get references to a sketch. The second problem is how to setup at programming level map the Line, Point, Arc and Circle from NaroCAD to SketchSolve semantics and after the SketchSolve is done, to make things back. Another small feature, yet useful is that those constraints are in a chain, so at programming level, the code at NaroCAD level is smart enough that by simply stating a shape, will build all the dependency chains to be computed in SketchSolve. To be both efficient, this code uses the GraphMapping component that compute back-references and get the mapped constraints.

So let's take a simple(st) case:
"NaroCAD have defined two points and one constraint (PointToPoint) and one point may be moved"
How the back logic works:
- the scene computes the back references: so P1, P2 are references by P2PC
- BFS algorithm will find in P1 -> P2PC -> P2
- a re-mapping will translate NaroCAD shapes and constraints will be converted in SketchSolve logic
- SketchSolve will solve the the constraint system and will retranslate shapes to make the system to work
- at the end shapes will be un-mapped from SketchSolve so the constraints will work accordingly