Starting in the 15th century, intellectuals and theorists began developing the techniques and visual language necessary to study, understand, review, and communicate spatial concepts through drawings and models. Drawing and drafting on paper has since remained the generally preferred method of conceptual design exploration, and designers and architects have honed the necessary techniques to explore, understand, and represent three-dimensional space with this two-dimensional medium. Today, design and especially conceptual design, has evolved into a highly iterative process that usually starts with rough doodles, sketches, and other methods for expressive, quick, and inexpensive exploration before moving the work into a more precise and less forgiving environment: the computer. Digital models already have the ability to offer designers more insights through the rapid exploration of variation, even automated iteration, and powerful simulation and validation, as well as the ability to routinely and to easily generate drawings. Even still, rough physical models and drawings are widely encouraged by educators and professionals prior to entering the digital realm, and drawing on paper endures as the de facto method of choice for designers to record and develop their ideas. Our experience and research suggests that the main issues preventing designers from fully embracing digital methods as viable alternatives or even improvements on their traditional mediums, particularly in the early-phases of the design process, are the limitations of the customary input technologies and methodologies as well as the subsequent interaction and representation capabilities available with and of the inputted geometry. Pen and multi-touch technologies have made big leaps in recent years though hardware specifications and costs still remain among the biggest hindrances; most importantly, currently affordable display surface areas are not sufficiently large or of adequate resolution for design type explorations. Our prototype 3-dimensional drawing platform was developed using a large format Microsoft Surface Hub, which we believe is the closest hardware solution currently available to an ideal high-resolution, multi-touch, drafting board. Moreover, Windows 10’s intrinsic cross-platform characteristics provide a framework for our prototype to also work on more inexpensive personal computers, such as Microsoft’s Surface Book, while the larger format displays remain cost-prohibitive. This thesis recognizes that a viable digital alternative to drawing on paper must look and feel good and must support pen and multi-touch input. Of course, the full range of possibilities that pens, pencils, markers, and paper mediums offer designers are very difficult to accurately simulate and render digitally, especially when drawing is considered a personal experience that can vary greatly from designer to designer. While we acknowledge that our platform will not be able to provide the full range of possibilities available in expression through traditional drawing, we believe that the added benefit of a more integrated workflow will overcome some of the shortcomings in expression and demonstrate a clear path for future research and development. Drawing plays different roles throughout the different stages of the design process and is also used to move ideas and intentions back and forth between those stages; from understanding others’ existing designs, to recording and developing one’s own ideas, to voluntarily misreading and reimagining those ideas. Trace paper or “red-lining” are popular common tools that allow designers and architects to draw and redraw over previous sketches or detailed drawings as they iterate, reference, and rethink past design decisions. This thesis demonstrates a more integrated and therefore more powerful way of drawing that recognizes the iterative nature of the design process and the apprehensions preventing designers from embracing digital drawing. By providing a flexible framework for iterative exploration within a 3-dimensional context, we demonstrate a valuable design solution and workflow that is not currently accessible by designers; one that blurs traditional distinctions between drawing and modeling. This thesis proposes that drawing can be more powerful in 3-dimensions, while acknowledging that 3d modeling is not drawing. We propose a 3d drawing tool, built over an existing 3d modeling ecosystem, which allows designers to do drawing, but within a 3d environment. More specifically, we have developed a system that allows 2-dimensional and 3-dimensional sketching to happen within a 3d scene, one that intrinsically provides a basis to transition back and forth more fluidly and intuitively between a hand drawing and a virtual model. We feel strongly that the best solution is one that works with existing tools that designers already find comfortable and that are an essential part of their workflows and processes. We therefore built our prototype 3d drawing platform (Cuttlefish 3D) over a popular 3d modeling software ecosystem (Rhinoceros 3D) that has a powerful feature set, a low cost of entry, and a passionate and dedicated user and developer base. In this way, a working drawing can directly become a working digital model and therefore be further and fully explored and developed within powerful 3d modeling software. We further acknowledge that most continued design explorations are part of an iterative process and that any viable solution should therefore provide the designer the ability to then sketch over and within a working digital 3d model and scene.