(I really recommend that you read this entire website before you start doing anything with OneTwo3DO...)
I designed this program with the highest possible compatibility in mind, so data to build a 3DO can be obtained from various sources, such as DXF, 3DO-Text by Paul Hoads Editor and self-defined ASCII files.

I have heard comments that it's pretty self-explanatory, but anyway here is a short guide what to do to build a 3DO from scratch with OneTwo3DO:

  1. Define Vertices yourself or load vertex definition from a file, using the Geometry Menu. Check the included sample files.

  2. Once vertices are set-up, draw coloured polygons or lines from these vertices by selecting them with the mouse, almost like using a CAD program. There's also an alternative method to define polygons or lines where vertex indices can be given manually from a drop-down-list. Everytime a polygon or line is about to be drawn, this method can be chosen.
    Note that although the line colors are correct, the polygon colors that are shown in OneTwo3DO are NOT the polygon colors that can be seen in GPL, unless you select the function Assign Texture-specific Background Colors to Polygons.
    The final 3DO colors are derieved from the texture which the particular polygon uses, whereas polygon colors in OneTwo3DO are only used for visualization purposes.
    However, the function Assign Texture-specific Background Colors to Polygons assigns these also in OneTwo3DO, to see how it will look like in GPL, which might not be the color of choice when editing.
    Uncheck Pick Polygon Colors Manually in Options if you don't care about the colors shown.

    All this is available from the Visual Elements Menu

  3. Prepare some Bitmaps (either new or converted from existing Mip's) and Load them, then use the Assign textures to polygons function from the Visual Elements Menu.
    There are plenty of mapping functions available there to adjust the appearance of the texture on the polygon.

  4. Once all polyons have been textured, write an ASE file and automatically convert it to 3DO, with an optional start of GPL to check the results immediately. Be sure to set the correct path informations in Options and place the required mips into the track folder before you do this.
You're set, but anyway check the tool tips and prompt for user action in the Log Window for more information.