There are several settings under three sections. These settings must be done before picking the object.
These two fields hold the result bitmap’s size in pixels. The max size for both fields is 4096. If the image size is large, image viewer may not be able to show it in 1:1 scale. In this case you will see a bad image on the viewer but the saved image will be OK.
2- UVW Channel:
This determines the mapping channel that is to be used in unfolding process. If the chosen mapping channel of the picked object does not contain any mapping info a warning dialog box will appear.
3- Pick Object
When you push this button Texporter wants you to pick an object to unwrap. When unwrapping the current settings will be used. If you change any of the settings, the image will not update itself: you should pick the object again.
If checked, the faces will be shown as filled areas using the color scheme selected in the "Colorize by" section.
If you check this option the face edges will be shown in the resulting image. You can choose to show all edges or only the visible ones.
For circular mapping types (such as cylindrical and spherical), to achieve seamless tiling, some faces may get negative mapping coordinates (or values greater than 1.0) . Normally such faces fall outside the unfolded image (because of their out-of-range value) and therefore when you fold back the unfolded image on your mesh you get a black region because of this missing info. To correct this check the "Wrap Around" option. When you do so, out-of-range mapping coordinates will be inserted back into the image from the opposite side. For planar mapping types simply leave this option unchecked.
If checked, the result image will not show the faces whose normals are pointing away from the mapping icon. This results a more clear image but prevents you from checking all the overlapped surfaces.
If checked only the selected faces of the object will be unfolded and shown. This gives less complex and more clear output which can be used if you want to paint only some part of the object.
If checked only the faces with the given material ID will be unfolded and shown. Again this gives less complex and more clear output. If you are working on a object with a multi-sub material assigned, this helps you to paint individual textures for each sub material.
When applying UVW texture coordinates, you can not always get a perfect mapping; there may be areas which share the same UV coordinate. This means some faces use the same texture region, in other words if you paint a texture for an area, the same texture will be shown somewhere else on the object's surface (where the same UV is used). To avoid this you should choose the most proper mapping type.
When you turn on this option, these overlapping areas will be marked in the given color showing you where overlapping occurs.
This is very similar to MAX's viewport "Smooth" and "Facet" options. When "Smooth Colors" option is activated the faces will be filled with smooth gradient colors interpolated between the vertices. If this option is turned off, on the other hand, faces will be filled with constant colors. This option is not available for some of the colorizing schemes (and ofcourse if the "Polygon Fill" option is turned off).