The Groups menu deals with face and texture groups. When you press F or V, the current Face or Vertex will be marked as selected ("tagged"). For this section, I will use Bigfoot as an example for using face and vertex groups.
Here I have tagged all the faces that make up Bigfoot's hood. Now I select the Store Face Group command, which brings up the following window:
For the name of this selection I enter "hood" and click OK. If I save this model, BINedit will store this face group information in the file {binname}.BIN.info, so that it can be recalled at any time you open the model.
Face selections are used for things such as texture mapping and for defining face types.
The "hood" face group that I just stored is listed here - I can simply type it in or select it and click OK, and the faces on the hood will all be reselected. Notice the "Add to current selection" checkbox - if you check this, not only will your face group be restored but any currently selected faces will also remain selected. If it is left unchecked, any currently selected faces will be deselected when you load the face group.
Note that you can also select to restore the unnamed group from this list, which will clear the current face selection.
Here I have tagged all the vertices on Bigfoot's tailgate. Now I select the Store Vertex Group command, which brings up the following window:
For the name of this selection I enter "tailgate" and click OK. If I save this model, BINedit will store this vertex group information in the file {binname}.BIN.info, so that it can be recalled at any time you open the model.
Vertex selections are used only with the Translate function.
The "tailgate" face group that I just stored is listed here - I can simply type it in or select it and click OK, and the vertices on the tailgate will all be reselected. Notice the "Add to current selection" checkbox - if you check this, not only will your vertex group be restored but any currently selected vertices will also remain selected. If it is left unchecked, any currently selected vertices will be deselected when you load the face group.
Note that you can also select to restore the unnamed group from this list, which will clear the current vertex selection.
This command brings up the following window:
From the drop-down menu at the top I can select which of the currently loaded textures I wish to map faces to. In the middle is a view of the selected texture with a wireframe of the selected faces laid over it - vertices are shown as red crosses, and the edges of the faces are displayed in reverse video. The buttons on the side allow you to flip the wireframe horizontally or vertically, and to rotate it 90 degrees clockwise.
By left-clicking a vertex and holding down the left mouse button, you can drag it to a new position, or you can left-click in an empty space and drag the whole wireframe to a new position. Right-clicking and holding down the right mouse button allows you to resize the wireframe - drag toward the top left to make it smaller, or toward the bottom right to make it larger.
The below image shows how the face selection could be mapped to the texture. Here I simply rotated the wireframe mesh, then resized and moved it to the correct position.
If you were to open this texture in a paint program, you would find that this is not how it appears - for some reason BINedit displays the texture flipped horizontally. You will usually need to check using the 3D textured view that you mapped the face group to the texture with the right orientation.
BINedit lets you play with a wide range of faces for your models:
0x19 Ignore Texture Coordinates (MTM) - This is an unusual face type for which, as the name implies, ignores vertex texture coordinates.
0xE Hellbender Face Type - Obviously, these are the face type used in Hellbender.
0x18 Normal Texture (MTM) - These are the standard MTM1 face types: non-shiny. They change brightness according to their orientation towards the game's light source, but that's it.
0x29 Shiny Texture (MTM2) - These are the standard MTM2 truck face types: shiny and reflective. They look cool but pose problems on computers using 3D accelerator cards when the model's vertex count exceeds 1000.
0x11 Transparent Color #0 (MTM) - These are the standard transparent MTM1 faces. Colour #0 (black) becomes transparent but all other colours stay the same, so you can get interesting looking "cut-out" shapes.
0x33 Transparent Texture #0 (MTM2) - These are the standard transparent MTM2 faces. They work in the same way as their MTM1 counterparts, except that it is not recommended to use the MTM1 versions on MTM2 models.
0x?? Unknown Face Type - This face type is assigned to faces of which BINedit can't recognise the type.
It is interesting to note that most of these face types are compatible with any of the games - for example you can have Hellbender face types in MTM2 if you really want to! - but they sometimes have unusual side effects.