3D Game Programming All in One (Course Technology PTR Game Development Series)

Load Model

Load a Wavefront OBJ formatted model from file. After it is loaded, you will see the texture map layout in the UVMapper window. If you don't, then there are no texture coordinates included in the model. You can fix this by choosing Edit, New UV Map (see Table 13.18).

New Model

This command gives you a method for adding or creating your own models from shape primitives. The primitives are box, cone, cylinder, sphere, and torus.

Import UVs

With this command you can import UV coordinate data that has been saved separately from a model.

Save Model

Use this command to save the UV mapping data you've created along with the model you originally imported.

Save Texture Map

You can save the texture map image using this command. You can then load that image as a template into a program like Paint Shop Pro in order to apply that "artistic magic."

Export UVs

With this command you can export only the UV texture coordinates you've created using this program, without the rest of the model data.

Settings

Here you can specify how many pixels on your screen correspond to a single measurement unit. The value you use depends on the scale of the model you are working with.

Select By

This command gives you the ability to select on-screen objects by facet (face) or by selecting the vertices. Usually you leave this set to Facet.

Color

This command will let you indicate how you want to discriminate the different parts of the display. Your choices are Black and White (no discrimination), by Group, by Material, and by Region. This capability is handy when dealing with a complex model.

Tools

This command provides three different functions: Fix Seams, Split Vertices, and Weld Vertices. MilkShape offers these same abilities, but it's nice to know we have access to them here as well.

Select

With this command you can refine your object selection ability. There are five modes: All, None, by Group, by Material, and by Region. The by Group, by Material, and by Region options each provide a Selection dialog box if these entities actually exist in the model data. Judicious naming of groups (meshes) when in MilkShape can be a great boon when working here in UVMapper.

Assign

Use this command to assign selected objects to an existing group, material, or region. Again, you would normally do this in your modeling program, but it's nice to have the ability here if you realize you've forgotten to assign some faces to a particular group.

Rotate

This command allows you to rotate a selection around any of the three axes—or all three at once, if you want.

New UV Map

This command provides several different unwrapping methods: Planar, Box, Cylindrical, Cylindrical Cap, and Spherical. The options available here are quite extensive so they warrant coverage in their own section, called "UV Mapping," in this chapter.

Tile

This command is complementary to the Select command. Using Tile you can specify how the program displays the different parts of the model; they can be visually organized (tiled) according to group, material, or region.

Statistics

This will report the current status of your model. This will tell you the total vertices, textures, normals, facets, groups, and materials. Bear in mind that while you are editing a model, UVMapper will temporarily increase the number of texture coordinates allocated to the model, and so this is not a good representation of the actual number of texture coordinates the model will have upon saving. A more accurate way to obtain this information is from within the MilkShape modeling tool.

Dimensions

This will give you the overall geometric dimensions of the model. This will report the minimum and maximum values along each of the three axes (X, Y, and Z).

Hot Keys

This command will give you a list of the available hot keys. Table 13.20 also contains a list of the UVMapper hot keys.

About UVMapper

This command gives you information about the version, how to contact the author, and where you can obtain an updated version of the program.

Esc

clears selection, undoes changes

Enter

clears selection, saves changes

Shift+number key

increases resize/movement amount

keypad *

quadruples size of selection

keypad /

quarters size of selection

keypad +

increases size of selection

keypad -

decreases size of selection

keypad #

moves selection

=

maximizes selection

.

snaps selection to facets

[

hides selected facets

]

shows selected facets

\

toggles facets on and off

'

hides unselected facets

uU/vV

resizes selection (fine)

x/X/y/Y

resizes selection (coarse)

Ctrl+x

inverts selection horizontally

Ctrl+y

inverts selection vertically

Ctrl+b

loads background

Ctrl+c

clears background

Ctrl+u

flips background horizontally

Ctrl+v

flips background vertically

Tab

toggles background display

t

triangulates object

Insert

checks for degenerate facets

Alignment

This allows you to specify the axis along which the model will be mapped.

Orientation

This allows you to alter the layout of the texture map template. It only has an effect when using the Split option (described later in this table). If you select Don't Split, the Orientation option has no effect. When splitting the model into front and back sections, you can have the two halves side by side (Horizontal) or above and below each other (Vertical). Which you want to use really depends on the geometry of the model. If you don't like the layout of the texture map after using planar mapping, try changing this option.

Map Size

This will specify the maximum dimension of the texture map template. Depending on the model it may be vertical or horizontal, but the texture map is guaranteed not to exceed this value in either width or height. One side will equal this value, and the other will be scaled accordingly.

Split

This option allows you to divide the texture map into front and back sections. (To adjust the placement of these sections, see the Orientation option earlier in this table.) You have three options. Don't Split will give you one map with the front and back facets on top of each other. By Orientation will calculate the facet normals, placing all facets that face toward the eye on one side, and placing all facets that face away on the other. By Position with Offset of allows you to divide the model based on geometry rather than facing. Using an offset of 0 will divide the model in half. You can adjust this offset to change how many facets are on each side.

Gaps in Map

This allows you to separate the sides of the box on the texture map. If the sides touch, sometimes you will see one pixel of the side on the front, for example.

Scale Result

Use this option to specify how much larger or smaller the resulting texture map should be.

Map Size

This will specify the maximum dimension of the texture map template. Depending on the model it may be vertical or horizontal, but the texture map is guaranteed not to exceed this value in either width or height. One side will equal this value, and the other will be scaled accordingly.

Split front/back

Setting this option will divide the model into six sections: front, back, top, bottom, left side, and right side. Uncheck this option if you want to combine top and bottom, left and right, front and back, giving you only three sections.

Gaps in Map

This allows you to separate the sides of the box on the texture map. If the sides touch, sometimes you will see one pixel of the side on the front, for example.

Scale Result

Use this option to specify how much larger or smaller the resulting texture map should be.

Map Size

This will specify the maximum dimension of the texture map template. Depending on the model it may be vertical or horizontal, but the texture map is guaranteed not to exceed this value in either width or height. One side will equal this value, and the other will be scaled accordingly.

Split front/back

Setting this option will divide the model into six sections: front, back, top, bottom, left side, and right side. Uncheck this option if you want to combine top and bottom, left and right, front and back, giving you only three sections.

Gaps in Map

This allows you to separate the sides of the box on the texture map. If the sides touch, sometimes you will see one pixel of the side on the front, for example.

Scale Result

Use this option to specify how much larger or smaller the resulting texture map should be.

Alignment

This allows you to specify the axis around which the model will be mapped.

Offset

When mapping a model with one of these methods (Cylindrical, Cylindrical Cap, or Spherical) the model is mapped around a center point. This center is calculated using the maximum and minimum geometry values along each axis. This works quite well for mapping a true sphere or cylinder, but if you have a model that is, say, a sphere with a spike on the side of it, the calculated center may not be what you want. To adjust the center of the model from what's been calculated, use this option.

Map Size

This will specify the maximum dimension of the texture map template. Depending on the model it may be vertical or horizontal, but the texture map is guaranteed not to exceed this value in either width or height. One side will equal this value, and the other will be scaled accordingly.

Rotation

Use this to specify how much, if any, rotation will be applied to the resulting texture map image template.

Gaps in Map

This allows you to separate the sides of the box on the texture map. If the sides touch, sometimes you will see one pixel of the side on the front, for example.

Scale Result

Use this option to specify how much larger or smaller the resulting texture map should be.

Spread facets at poles

Oftentimes facets are squeezed together when the mapping occurs, especially at places like the "poles" (the tops and bottoms of the map, just like on maps of the Earth). With this option set, the resulting map will spread the facets at the poles to alleviate the pinching effect.

Alignment

This allows you to specify the axis around which the model will be mapped.

Offset

When mapping a model with one of these modes (Cylindrical, Cylindrical Cap, or Spherical) the model is mapped around a center point. This center is calculated using the maximum and minimum geometry values along each axis. This works quite well for mapping a true sphere or cylinder, but if you have a model that is, say, a sphere with a spike on the side of it, the calculated center may not be what you want. To adjust the center of the model from what's been calculated, use this option.

Map Size

This will specify the maximum dimension of the texture map template. Depending on the model it may be vertical or horizontal, but the texture map is guaranteed not to exceed this value in either width or height. One side will equal this value, and the other will be scaled accordingly.

Rotation

Use this to specify how much, if any, rotation will be applied to the resulting texture map image template.

Gaps in Map

This allows you to separate the sides of the box on the texture map. If the sides touch, sometimes you will see one pixel of the side on the front, for example.

Scale Result

Use this option to specify how much larger or smaller the resulting texture map should be.

Spread facets at poles

Oftentimes facets are squeezed together when the mapping occurs, especially at places like the "poles" (the tops and bottoms of the map, just like on maps of the Earth). With this option set, the resulting map will spread the facets at the poles to alleviate the pinching effect.