COMS W4172: 3D User Interfaces—Spring 2014

Prof. Steven Feiner
Date out: February 27, 2014
Date due: March 11, 2014

Assignment 2:  Making It

For this assignment, you will be exploring and evaluating the user interfaces of two applications that allow you to create and manipulate 3D models: 3DTin and Tinkercad. (Note that both 3DTin and Tinkercad have paid versions that provide extra functionality.  For purposes of this assignment, please use only the default free versions.) Both of these are web applications that use WebGL, and therefore require a compatible browser, such as Firefox. (There appear to be problems with some of the 3DTin operators in Chrome and Safari, so we suggest that you use Firefox.)

You should begin by acquainting yourself with both applications, being sure to keep track (of your first impressions (ideally by writing or recording). Both have have integrated web-based documentation, and you should refer to it (and take it into account in your evaluation).

Description and Heuristic Evaluation

Your evaluation should have two main sections, both based on your experience using the applications to create and manipulate models, and reading the documentation. In the first section, you should address the ten usability heuristics introduced in class (, mentioning specific examples of how well 3DTin and Tinkercad do or do not satisfy each heuristic. Please do this by creating a subsection for each heuristic in which you discuss both applications, being sure to distinguish between the two applications.

In the second section, please pay special attention to the following specific areas, taking into account both cursor and keyboard interaction:

  1. Camera manipulation. How the user controls camera position, orientation, and field of view. The space of possible camera configurations supported in each application. Relationships between changes in the different variables and how they are controlled in the user interface. (In your writing, please be sure to be clear about whether you are referring to a change in camera position vs. a change in camera field of view.)
  2. Selection. How the user selects or deselects one or more objects or groups of objects.
  3. Manipulation. How the user manipulates existing shapes, including adding and subtracting shapes to make new ones.
  4. Creation. How the user creates new shapes.

For each of these four areas (each of which could be made into its own subsection), describe and compare the techniques that allow the user to accomplish their tasks for both applications. Here, it will be useful to think of some specific users and tasks that they might want to perform. Explain how these techniques work well, how they come up short, and how they could be improved. In considering these issues, please address any of the ten usability heuristics that you feel are particularly relevant. However, you are not limited to these heuristics, and should mention any issues that they do not cover. (If you are familiar with any other systems that support similar functionality, you are welcome, but not required, to optionally draw comparisons to them.)

Note that this is a written analysis/essay assignment and there is no code involved. Please think critically and provide thoughtful, well developed descriptions, explanations, and comparisons (not a bulleted list).  There is no required minimum word count, and you are not being asked to write documentation, although you are encouraged to refer to the existing documentation without repeating it. Instead, you are being asked to evaluate the usability of the systems. Therefore, you will need to make assertions about the artifacts you are evaluating (3DTin and Tinkercad) and to defend assertions you make by citing the heuristics or other criteria addressed in your book or in class, and explaining how the two applications follow or violate them. Your assignment should also include an introduction and conclusions.

Please include relevant screen shots in your evaluation, integrating them into your document, instead of including them as separate images.


Imagine that you were about to interview for one of the companies whose applications you are analyzing, or perhaps another company interested in creating a competing application. As you do this assignment, try to show off your understanding of the two user interfaces and the tradeoffs between them in a way that would inspire confidence in a savvy technical interviewer (i.e., not the person from human resources).

Please note that both applications live "in the cloud."  And, that means you are at the mercy of each application's website for it to work, and you may even experience periods of occasional downtime.  Please make sure that you do not leave the assignment for the last minute, only to discover that a website is down—we will not be offering additional late days/hours to compensate for downtime.

As you use each application, please pay attention to the use of modes, and how each application supports identifying and switching between modes.

What to Submit

You should submit your written evaluation as a PDF file, although Word files (with properly embedded images) will also be accepted. It is your responsibility to make sure that any file you submit is virus-free. Note, again, that screen captures should be integrated into your document, and not included as separate images. Please be sure that your name and uni appear at the beginning of the submission.

How to Submit

Your assignment should consist of a single file named "YourUNI_Assignment2" (with the appropriate filetype extension) that you will submit through CourseWorks. Here are the steps:

  1. Log into CourseWorks.
  2. Select Drop Box from the left hand navigation pane.
  3. Expand the COMSW4172_001_2014_1 Drop Box folder. You should see a folder with your own name (if you do not, please email the TA).
  4. Select Upload Files in the drop-down list to the right of your name.
  5. The Upload Files page will load. Choose your PDF (or Word) file using the browse dialog window that appears after pressing "Choose File."
  6. After choosing your project, enter the display name.  It should follow this convention: "YourUNI_Assignment2."
  7. Press "Upload Files Now."

Please try to submit well before the deadline, since CourseWorks can sometimes become busy and slow. You may use any number of your remaining late days on this assignment, but please start early!