Modeling a free form object, is a complex computer engineering task, in particular, when the user has no deep knowledge about computer aided geometric modeling. The most difficult part is to assign the often ambiguous depth to the two dimensional drawing, which only exists in the users imagination, while keeping the process as natural as possible.
This thesis focuses on the subject of manual drawing and related algorithms, and aims to design and develop a 3D demo application.
The main design goal is to support a certain workflow, which is similar to the traditional paper and pencil based sketching. The system avoids the usage of the B-spline based modelling, which is common in professional CAD softwares that may appear to be somewhat artificial for users. An important aspect was to design an internal data structure that maintains the compatibility with other CAD systems, and produces useable models for downstream applications. The user interface applies a simple toolbar, and a few, easy to learn gestures, to create primitives (points, curves) to the model, and define working surfaces based on them. The target device is a stylus equipped, 10.1 inch tablet, running Android. (Samsung Galaxy Note 10.1 2014 Edition)