Interfaces

The most common human interface device with a computer is a mouse and keyboard. We’ll take a look at other useful interfaces for working with 3D modeling software.

Graphics tablet

A graphics tablet is a special drawing board that works with a pen-like stylus. It’s been the primary interface for use with graphics and digital painting software and it can be useful for 3D sculpting as well.

A graphics tablet system is similar to writing with a traditional pen on paper. A stylus has a pressure sensitive nib which responds to the pressure exerted on the graphic tablet’s surface. This allows a more natural method of manipulating brushes and sculpting tools within 3D modeling software.

Some software is not capable of utilizing the pressure sensitive capabilities (such as Meshmixer), but can be still used as a mouse type device. Hard modelers (such as Sketchup Make or Fusion 3D) are cumbersome to work with while using a stylus. They are better suited with a traditional mouse.

Wacom is one maker of the graphics tablet. The Bamboo Capture Pen and Touch Tablet is featured here and costs 100 USD. Newer models are available and they vary in price depending on the size. It’s fully compatible with 3D-Coat.

Space mouse

Most 3D modeling software requires toggling (by way of menu selection or by keyboard) in order to use the mouse to navigate the camera view. This interrupts the primary work in order to gain a better view.

The space mouse is an additional peripheral device that works in tandem with other peripherals such as a mouse or graphics tablet. It allows navigation with the left hand and mouse usage with the right hand (or vice versa). This allows for 360° of navigation freedom with zooming and panning. It also relieves wrist fatigue by separating the work load between two hands.

3Dconnexion is one maker of the space mouse. They have various models, some incorporating an ergonomic platform that has programmable keys and LCD displays.The SpaceMouse wireless is featured here and it’s available for about 125 USD. It’s fully compatible with 3D-Coat, Sketchup Make and Fusion 360.

Next: 3D scanning. There has to be an easier way of creating 3D models, right? 3D scanning may provide you with the solution.

3D Modeling

There’s a variety of 3D modeling software offering many types of approaches for creating three-dimensional forms. Deciding which one to use will depend primarily on the style of work, the steepness of the learning curve, and how much the software costs.

Optimizing the 3D modeling experience

3D modeling software can be divided into two kinds of modelers, hard and soft modeling. Both approaches have their advantages and disadvantages, yet by combining the software a workflow can be created that will optimize the 3D modeling experience.

For example, the concept is hard modeled as a geometric form with Sketchup Make. And then soft modeled with Meshmixer. By using these two different software programs, the basic structure could be quickly built with precision and then modeled further into a natural organic form. Utilizing these two approaches, virtually anything can be modeled.

Let's take a closer look at this concept.

Soft modeling

Soft modeling works best for creating organic forms. By using an assortment of tools, such as flatten, pinch and smooth, the surface of a model can be shaped into realistic forms and textures. The following soft modeling software is recommended for its functionality and modest learning curve.

Meshmixer

Meshmixer has a good variety of sculpting tools that can be adjusted for different characteristics, such as strength, size, and depth. It also utilizes a stencil feature which allows for the application of physical textures on the surface of the model. One of the most significant features of Meshmixer is its collection of parts. 

A variety of primitives, shapes, and human and animal parts can be added together and transformed in countless configurations. These parts can be utilized to create base forms that can be reshaped later with the sculpting tools.

Meshmixer is provided free by Autodesk and it can be downloaded at their site http://meshmixer.com/download.html.

3D-Coat

3D-Coat is a professional digital sculpting program that works more like real clay than most other programs. Using a voxel (volumetric) system, it actually carves into the model as a solid, rather than displacing the topological surface. This allows for digging into the actual form (creating negative space and holes) with much better results than other soft modelers.  

3D-Coat also has a powerful layers system called a voxtree. This allows modeling of complicated forms that have many parts. Individual parts of the model can then be isolated for specific modeling or they can be exported as individual parts for 3D printing. This creates the possibility of creating sculptural assemblages larger than the build volume of a 3D printer.

3D-Coat incorporates a 3D painting system as well. The model can be rotated and digitally painted with tools that work very similar as the tools in photo editing software. If your sculpture is to be painted with traditional materials, this can be a very quick means for pre-visualization.

3D-Coat is a commercial program offered by Pilgway and it can be downloaded at http://3dcoat.com/download/. A 30 day trial is available with all features intact. An amateur version with less features is available for 99 USD. Full professional version is 379 USD.

Hard Modelers

Hard modelers work more like CAD drafting programs. They create straight lines and curves with the precision of real world measurements. Because of these traits, they can be useful for creating parts that need to be precisely integrated with objects. They also model complex geometric forms with far greater ease than a soft modeler. The following hard modeling software is recommended for its functionality and low cost.

Sketchup Make

Sketchup Make has one of the lowest learning curves for a hard modeler. It works by drawing lines and basic shapes (such as rectangles and circles) and then extrudes these drawn shapes into a 3D model. 

It has an intuitive approach to modeling that makes it easy to build complex mechanical parts or geometric constructions that can be exported into other programs for soft modeling.

Sketchup Make is a free program offered by Trimble and it can be downloaded at http://www.sketchup.com/download. It begins with a 30 day trial as the Sketchup Pro version. The pro version costs 695 USD and adds more functionality, such as solid modeling tools.

Fusion 360

Fusion 360 is a powerful tool for creating industrial and mechanical designs. It models with a system of T-splines, which are mathematical representations of curves and surfaces. The learning curve for this software is moderately difficult due its many features.

One of it’s most significant features is its ability to create a shape around an imported mesh (such as a 3D scanned model) and copy the contour of the form. This provides the artist with a means for creating precise parts that can be attached to real world objects.

For an artist who works with hard edged forms that rely on geometric precision, Fusion 360 will provide the best tools for creating a 3D model.

Fusion 360 is a commercial cloud based program offered by Autodesk. It has a 30 day free trial with all features intact. Professional usage has a 30 USD cost per month or 300 USD cost per year. Hobbyist and startup companies can register for free use.

Up Next: Interfaces. Working with a 3D modeler is more enjoyable if it becomes more accessible as a tool in an artist’s hands. We’ll look at some affordable human interface devices.

How 3D printing works

3D Modeling

3D printing begins with conceptualizing an idea as a digital model. There are many different methods for creating digital models. The most common method is by using  3D modeling software or by 3D scanning physical objects. The 3D models generated with this software must be a solid (more on this at the Mesh Tools page) and exported as a .stl (STereoLithography) file. This is the file format for 3D printing.

The slicer

For 3D printing, the .stl file has to be prepared with software that’s called a slicer. The slicer works by taking your 3D model and cutting it up into many thin horizontal layers.

At each layer the slicer also adds the instructions your 3D printer needs in order to fabricate this layer. After slicing, this new information is saved as a .gcode file.

The Host

The host is simply a software program that allows you to manually control your 3D printer and it communicates the

information stored in your .gcode file to the 3D printer’s onboard computer. There are many different hosts available. They all have a basic user interface (UI) with some sort of graphical representation of your 3D model.

What is a 3D printer?

A 3D printer is a robotic device that’s controlled by an onboard computer system.

 It can move precisely in all three dimensions of space and control aspects of its functions by monitoring its components by the use of sensors. Ideally, once a 3D model is prepared and loaded, you can walk away and the 3D printer will fabricate your model without further human assistance.

The FFF process

There’s more than a handful of unique 3D printing technologies in use today. This site explores a process called fused filament fabrication (FFF). The FFF process works by heating a thermoplastic filament by way of a toolhead called an extruder. Guided by the instructions provided in the gcode of the 3D model, the extruder will create a thin horizontal layer of plastic that follows the contour of the model. It then lifts slightly and builds another layer on top of the previous layer. The 3D printer will continue to build these layers, one on top of another until the entire 3D model is fabricated.

This method of fabrication can create virtually anything by using many types of thermoplastics. Thermoplastics can consist of an assortment of fillers such as, carbon fibers, wood, stone, kiln ready clay and metal, providing the artist with a variety of materials to work with.  Even transparent and flexible materials are available for 3D printing.

Large scale 3D printed sculpture with RoboSculptor

The continual testing of the RoboSculptor has finally yielded its first large scale print. There were several failed attempts during the initial trials after glitches were encountered in several parts of the system. Apparently key components that I previously held infallible were not appropriate for larger print runs, but the problems were rectified and now the system is ready for some serious work.

The first large scale print almost maxes out at 18 inches high. The width and length floated somewhere within the 13.5 x 15 inch XY plane.

Slicing the model has been problematic with most of the open-source slicers. The model has 588,544 polygons and the STL file is 28MB in size! I had problems with memory allocation with Skeinforge and Slic3r was unstable. Cura seems stable and it completed without apparent errors, though it was slow and unresponsive at times. The best solution was to use  the commercial slicer Simplify3D.

Repetier-Host and Printrun have been my favorite hosts, but both are heavily burdened with such large files. Printrun develops memory buffer errors and is unstable. The best solution was to use Simplify3D as the host as well..

Of course with the support material that is generated, the print becomes even larger and this in turn uses more filament. 3 rolls of 1kg semi-transparent orange PLA was required.

This is the longest print run to date. The entire print time for this sculpture was 3 days and 14 hours!

Once the print was finished, the support was pulled away from the sculpture. Most of it released easily, though the use of pliers were of great help.

The finished piece can now be lightly sanded and painted.

The sculpture was printed with a 0.4mm layer resolution. This would normally be  considered a low resolution surface for a smaller print in the 50 to 80mm range, but is actually fairly uniform and unobtrusive for an object in this size range.

An interesting feature about the the semi-transparent filaments is the effect that is achieved when light is shown through the object.

The internal structure of the infill in combination with the layer texture creates a beautiful surface that has to be seen in person to fully grasp the three-dimensional effect.