For our June meeting, Shawn Melton of Straight and Narrow Workshop, spoke about various aspects of industrial design and how he uses them in his newly founded social-enterprise. Shawn’s workshop focuses on helping ex-felons to obtain experience, skills, and a well paying job. They become more than just a person with a criminal history; they become skilled, and valuable workers.
The primary talking points from Shawn’s presentation were as follows:
The Design Process
One of Shawn’s primary focuses was on the design process. He stated that there could be “10 ways to do anything.” This is an important thing to understand when creating anything as the options that are available to a designer can be seen as either overwhelming or beneficial. The important thing is to know your options and know that there is no set way to do one thing.
When designing, Shawn stated that before starting with a modeling software, it’s often better to start with paper and do simple sketches as these are much easier to fix or change. The main focus with these sketches, he stated was not about getting every detail but rather the “point is to make mistakes as fast as possible.”
After making your sketches, you need to choose the best 3D modeling software for the job, and this is all dependent on what that job entails. It could even be that more than one software used in collaboration with another could be the most beneficial to your design.
Types of Modelers
He broke down the 3 types of 3D modeling software that are commonly used among designers: polygonal, nurbs and parametric.
Polygonal modelers break down complex geometry into faceted faces. Typically, polygonal modeling software allows quick modeling as it is not dependent on dimensions and tolerances. This allows designers to create very complex designs quickly. Polygonal software such as 3D Studio Max, Maya and Blender, can be used to easily add textures to objects in the form of jpeg or tif images on top of the 3D model. He demonstrated this with the following pictures where the wood flooring had individual jpeg textures laid on top so that each individual piece of wood had a unique appearance. Software like 3D Studio Max and Blender are also used heavily in the 3D animation space such as in CGI movie effects and in video games. Polygonal models are great for creating things very quickly however keep in mind that if you want to make changes to your model it can take quite a bit long than it would in traditional CAD software; this is due to the fact that the dimensions do not scale with one another. If you go back to change a section of your model, the rest of the object will not scale to match.
A NURBS, non-uniform rational basis spline, based modeler does not contain points in the same sense that Maya and other polygonal modelers do. A NURBS surface is the function of two parameters mapping to a surface in a 3D space. Think of a NURBS surface as an infinite amount of “lofted” 2D curves. Their surfaces are changed by changing the “control points.”
Using a NURBS based modeler is useful when trying to make the complex geometry of an object faster than you could in CAD and the model will still be compatible with most CAD software. The ability to make these complex geometric shapes comes with a cost however. Similar to polygonal modeling, going back to make changes still takes a great deal of work, because there are no relationships between the parts of the whole.
NURBS surfaces are useful for 3D scanning, because you are able use a 3D scanner to generate a “point cloud”. From there the software creates a “mesh” file by converting this mesh to a best-fit “NURBS” surface, and then you are able to import this into a traditional CAD software where you can set up relations and modifiable features.
Photo courtesy of: http://www.laser-scanning.co.uk/reverse-engineering/nurbs-surface-model
Parametric modeling allows designers to create a 3D representation of an object and make easy revisions to that object down the road. If a designer modeled up something like a workbench to specific dimensions, they could later change a dimension and the 3D model will grow or shrink to reflect the change.
Parametric modeling software is also ideal when someone wants to create a family of objects that may be slightly different. The manufacturer of the workbench referenced earlier could have only a couple of parametric models that could represent hundreds of variations of the same product. These “traditional CAD” software packages unfortunately don’t like to play nice with one another so if you are working with multiple users on different programs, you have to export the models into polygonal or NURBS formats. Parametric modeling is also slower to start out on as you have to set up the relationships early on. This can slow down the design process because you are not able to concept ideas as quickly as with the other modelers.
A company that was hired to design the drill pictured below would probably start concepting the form and overall shape of the drill using polygonal and/or NURBS modeling techniques. Then CAD for the components that are easily controlled via parametric software, i.e. things such as the motor, gears, connectors, fasteners.
For full meeting pics & some of Shawn’s work: CLICK HERE!
Authors: Chris & Amber Kaminsky