Star Gazers

Whether you want to make your first try at UV mapping a model for texturing, or if you are a veteran at UV mapping with other programs, there is a new utility out there called Ultimate UnWrap3D that is worth checking out and it's the subject of this month's tutorial. 

The last seven images act as links to larger versions of those images.  Just click on the image you're interested in, and a full size 1024 by 768 pixel screenshot should open in another window.  If this larger image doesn't appear at full size, then let your mouse hover over the image and click on the magnification button that appears.

This tutorial uses a lot of images.  To speed up the download times, it has been broken up into six pages.  A navigation bar is provided on the bottom of each page.  If you download the PDF for Adobe Acrobat, you will see that version of the tutorial is arranged as a single long page since downloading is not an issue.

UV Mapping Defined

UV coordinates are the “pins” used to attach a texture to a model.  UV mapping is the process of applying UV reference coordinates to a 3D model.  The two axes of the image are called U and V since X, Y, and Z are already commonly associated with the 3D mesh.  These coordinates are used as a reference that controls how a flat 2D texture image will be wrapped around the model.  You can choose mapping methods such as spherical or cylindrical that are closest to the original shape of your model but will probably produce some distortion.  You can also map the model on a facet-by-facet basis, or ‘unwrap’ the model to produce a distortion free map that is a lot harder to paint, unless you have a system for projection painting your textures directly onto your mapped models.

What is UnWrap3D?

UnWrap3D is a standalone program developed by Brad Bolthouse for UV mapping and editing on any PC with a Windows operating system.  It features a wide variety of mapping modes, and the ability to simultaneously display a 2D view of the UV template and texture map and multiple 3D views of the textured 3D model.  Nearly every menu option may be assigned custom keyboard shortcuts by the user.  It also allows the user to create new groups in a model and to quickly group a model that was imported without any groups.

Strategy for UV Mapping with UnWrap3D

(1)  Import the model into UnWrap3D.

(2)  Select the model and apply a mode of UV Mapping that gives a good general view of the model in the 2D window.

(3)  Apply a reference checker pattern to the model to check for distortion.  If the checker pattern is distorted, any texture applied will be distorted as well.

(4)  Select different parts of the model and apply the mapping mode that best fits each part.

(5)  Edit the positions of the UV coordinates to minimize distortion in problem areas where stretching or smearing occurs.

(6) Pack the UV Map to minimize the wasted space.

(7) Export the UV map for use as a template in Photoshop, or the 2D painting app of your choice, and paint the texture map, then import your texture map and see how it fits the model in the 3D window.

(8) When satisfied, export the UV mapped 3D model for final rendering in the 3D app of your choice.