Improving Parametric Design in CAD Applications

Computer-aided design (CAD) has transformed how we create and modify models. One exciting feature of CAD is parametric design, which allows users to create models using Variables that can be changed to produce new versions without needing to start from scratch. This flexibility is especially useful in fields where customization is essential, such as digital fabrication. However, parametric design comes with challenges, especially when using programming-based CAD applications.

In programming-based CAD, users define their models using a programming language within a code editor. The application then shows a visual representation of the model. This setup often requires users to write complex programming and math expressions to describe the geometry of their models. Unfortunately, many of these applications do not provide sufficient support to make this process easier, resulting in an experience that can be overwhelming for users.

To improve the process, we propose a method that helps users retrieve important expressions from the visual representation of a model so they can use them in their code. This approach simplifies the design process, making it more accessible to users, especially those new to CAD.

#The Basics of Parametric CAD

Parametric CAD allows users to make reusable models by integrating variables into the geometric properties of objects. Adjusting these variables can help generate various versions of a model. This method significantly benefits areas like digital personal fabrication, where users can customize models without needing to redesign them entirely.

However, creating designs in parametric CAD can be challenging. Users define models in code using programming languages, and the application generates a visual representation after compiling the code. This process demands a solid understanding of programming and mathematics, which can be a barrier for many users. As a result, users may struggle with accurately describing their geometric properties, particularly when trying to link different object properties together.

#The Need for Improved Support

In many programming-based CAD applications, there is a lack of assistance for users trying to create Parametric Designs. This shortfall can lead to confusion and frustration, particularly for those who do not have strong programming or math backgrounds. Users often find themselves grappling with complex code, trying to understand how to align parameters accurately with the visual representation of their models.

Recognizing these challenges, we propose a solution that will allow users to extract important parametric expressions directly from the visual representation of a model. By doing this, we aim to streamline the design process and reduce the barriers that prevent newcomers from fully engaging with parametric CAD.

#A Solution for Parametric Design

Our approach involves a feature that allows users to select components directly from the visual representation. By clicking on elements in the model, users can retrieve their parametric definitions. This method simplifies the process of defining geometric properties and makes the overall experience more interactive and engaging.

We developed proof-of-concept software that implements this concept within an existing CAD application. In our testing, we gathered feedback from eleven users who worked with both the original application and our modified version. Their experiences suggested that our solution could help lower the chances of design errors, enhance user interaction, and reduce the skill level needed to get started with parametric CAD.

#The Role of Variables in Parametric Design

In parametric CAD, variables play a crucial role in defining the geometry of models. By using parameters, users can control dimensions and relationships between different objects. For instance, a variable can dictate the height of a cube while also positioning another cube on top of it. This connection ensures that adjustments made to one part of the model affect related components correctly.

Despite the advantages of using variables, many users often struggle with correctly formulating their expressions. The complexity of spatial reasoning and the mathematical skills required to derive these expressions can lead to mistakes, even among experienced users. It is common for users to misalign parameters, miscalculate the necessary expressions, or confuse variables, leading to undesired results in the final model.

#Improving User Experience

To address these issues, we wanted to understand better how users currently define geometric properties in parametric design. A formative study analyzing various models showed us that most users define these properties as linear combinations of existing parameters. This insight helped us shape our design goals for a bidirectional programming application that simplifies the process of creating parametric designs.

Our modified program allows users to interact directly with the visual representation, facilitating the extraction of essential information they can use in their code. By making this data easily accessible, we aim to enhance the user experience when working with parametric designs.

#The Importance of Interactivity

Interactivity is a key factor that can enhance the usability and effectiveness of CAD applications. Traditional programming-based CAD approaches often separate the user from the model, requiring them to switch back and forth between visual representation and code. This disconnect can create confusion and slow down the design process.

By allowing users to interact with the model directly, we reduce the mental load often associated with navigating complex code. Users can see their design changes in real-time, allowing for quicker adjustments and more intuitive design processes.

#The Evaluation

To evaluate our solution, we conducted an experiment with participants who had varying levels of experience with parametric CAD. They were tasked with creating models using both the original application and our enhanced version. Participants shared their thoughts on the challenges they faced in parametric design and how our modifications helped them.

The results indicated that users found our solution easier to use. They reported experiencing fewer errors, requiring fewer attempts to achieve successful placements, and generally feeling more satisfied with the overall interaction. This feedback supports our hypothesis that allowing users to gather information from the visual representation of their designs can significantly improve their experience with parametric CAD.

#Conclusion

Parametric design in CAD offers exciting opportunities for customization and efficiency. However, the complexity of programming can often deter users, particularly those without strong technical backgrounds. Our proposed solution addresses these challenges by enabling users to extract important parametric definitions directly from the visual representation of their models.

We believe that by enhancing interactivity and simplifying the design process, we can lower the barriers to entry for newcomers and improve the overall user experience for everyone. As CAD technology continues to evolve, we hope to foster a more inclusive environment where individuals can fully engage with parametric design, unlocking their creative potential without being hindered by technical obstacles.