Global Mapper’s 3D functionality has been on the rise over the last couple of years. One of the more creative improvements was the addition of 3D point styles. They allow users to pick from a library of 3D models, and place them as points for better visual representation of their data. The 3D point styles can be placed individually, assigned to an existing feature type, or extracted from LiDAR. The point style options range from trees to push pins, and more are being added as updates roll out. The creation of the 3D models used in the library is a multi-step process, with plenty of scope for creativity.
Technical Considerations When Designing 3D Models in Global Mapper
Global Mapper is a Geographic Information Systems program that is embracing the new 3D age, but its first concern is always the accurate representation of large quantities of data. The unique context of its 3D engine raises some considerations that need to be addressed when creating each 3D asset. The most pertinent issue is the amount of models that need to be displayed on screen at once. In order to mitigate lag, all models made for Global Mapper are limited to five hundred polygons or less, and they are unable to take advantage of Alpha mapping or Normal mapping. This creates a challenge for the artist to produce a model that is both within the guidelines of the program, and also universally readable as the object it represents. In the future, Global Mapper’s 3D model rendering capabilities will be improved as we continue to add more and more 3D functionality.
3D Model Creation Process in Global Mapper
The first step to making any 3D point style is finding a need to fulfill. Many of the models are based on existing 2D styles — some were requested, while others were added to enhance our fun factor. Examples of the process are shown below using the newest model, Snowy the snowperson.
The creative process begins on paper, the model is sketched out. This allows the artist to plan the design, and get a rough estimate of the polygon count. The actual 3D work is done in a program called 3ds Max, a 3D modeling application from Autodesk.
First the model is created with the polygon count carefully considered. Each individual piece is modeled separately and aligned to fit together. Then the mesh is unified, creating one object. After the model is finished, the mesh needs to be unwrapped, which is done directly in 3ds Max.
Unwrapping is the process of creating a flat representation of the 3D model on a 2D plane, called a UVW map. The model is broken up into sections for easy texturing, minimal stretching, and to hide the seam where the texture edges meet. The snowperson in this example was broken down into nine UV shells. The orange nose is four identical shells perfectly overlapped, sharing the same material image.
When unwrapping a model, a checkered pattern is applied to properly display the texture mapping, allowing the artist to manipulate the shells and reduce distortion. The nine UV shells of Snowy share a single 1024×1024 PNG image created in Adobe Photoshop.
After the texture is created, it is applied to the model in 3ds Max using the material editor. The first application is often not perfect, so the material is created using the PSD file directly from Photoshop. Using the PSD makes adjusting the texture easier, because saving the Photoshop file automatically updates the material in 3ds Max. When the texture image is completed, it’s added to the material editor as a PNG, and the model is exported as an OBJ file. In the accompanying image you can see two identical materials, one is the PSD for editing, and the other is the final PNG.
When the model is exported as an OBJ, it then can be imported into Global Mapper and exported as a Global Mapper Package file to be added to the shipped 3D point style list.
Stephanie Martini is a Quality Assurance Technician and 3D artist at Blue Marble Geographics. She is lead QA for the Global Mapper 3D Viewer, and creates all 3D assets used in Global Mapper. Prior to joining Blue Marble in 2014, Martini spent four years training for game art and design, and got her BA from Alfred University in New York. She aspires to live long enough to have her consciousness downloaded to a computer, and join her mind with the AI that will inevitably control our world.