Details for Dec-1 beta

 From:  Michael Gibson
Changes for the Dec-1-2006 beta:

Added some additional ways to control the meshing when saving to .obj or .stl files. More details and examples on this below.

The mesh dialog remembers its placement now.

When the mesh dialog is showing, there is now a readout in the upper-right corner of the main window (where command options normally are shown) that gives the total number of polygons and points for the current meshes.

Smoothing groups are written to .obj files. Polygons that share vertex normals are grouped together with a smoothing group. But it doesn't seem like very many programs read this data from the .obj file right now.

Optional scale factor for OBJ export. You can cause MoI to scale .obj output by setting this in the moi.ini file (just add it if it is not present already):
[OBJ Export]

A variety of bug fixes for some shapes that made incorrect meshes.

There is some non-mesh stuff too:

Enabled reverse views - Bottom / Back / Left. To get a reverse view, click on the view control again after it is active. So for example to get the bottom view, set the "Top" view in the toolbar, and then click on "Top" a second time and it will flip to "Bottom". Click on it another time to flip it back.

Alternate way to zoom - Alt+ctrl+left drag in a viewport, or ctrl+right drag to zoom, for compatability with other software.

Fixed the File open / save dialog so it can be resized.

When un-hiding objects, they are now selected.

Some other miscellaneous minor bug fixes.


Ok - this section has more details on just the meshing controls.

The mesh dialog can be expanded by the arrow in the lower left to show more options.

Welding - by default .obj meshes are now welded, this can be controlled by checking the option on or off. Welding refers to points along edges, for whether polygons share a single point in common (welded), or whether the polygons on each side have their own individual points which are stacked up in the same location (unwelded).



Some systems may have problems with welded points and might function better with unwelded, and sometimes you may want to have unwelded points for certain special effects, such as doing a sketch rendering - unwelded edges will get an accent line in a sketch rendering.

Split larger than - You can enter a distance here which will force additional subdivisions of quads larger than this value. This can be used to add detail to large areas that have shallow curvature. Areas of shallow curvature will tend to get few polygons in them because the regular density control that is adjusted by the slider is based off of curvature, not lengths. "Split larger than" only affects curved surfaces, not planar surfaces (Edit - whoops, it looks like there is a bug where it does affect planar surfaces too, I will be fixing this for the next beta).

Here is an example of an larger area that didn't get very many polygons:

By entering a distance of 5.0, it will force more divisions there:

Avoid smaller than - You can enter a distance here which will restrict the number of subdivisions for quads that are smaller than this value. This can be used to reduce the number of polygons generated in small areas - normally the same density can be generated in both small and large areas because it is controlled only by the curvature. This is good if you are going to be zooming into a smaller area, but if you're never going to zoom in to a small area you may wish to have fewer polys there.

Here is an example of a small area that is getting quite a few polygons:

By setting an "Avoid smaller than" distance of 0.5, it will reduce the number of divisions there since this feature is close to that size:

Aspect ratio limit - you can enter a value here to force additional subdivisions for quads that are short in one direction but long in another. This affects all surfaces, including planar ones. Here is an example of a mesh with long and skinny quads:

If we want to get more regularly sized quads here, we can enter 2 in the aspect ratio control, which will force a division in any quad that has one direction more than twice as long as the other:

After you enter a value in any one of these 3 controls (Divide larger than, Avoid smaller than, and Aspect ratio limit), you need to push the "Update mesh" button to see the change reflected. It doesn't automatically do it because it can be fairly time consuming to create the mesh and you may want to tweak each of these values a little bit before doing the update.

If you want to turn off any of these constraints, you can either use backspace to clear the value, or enter a value of 0.

Please let me know if you run into any problems when using these controls or have any additional questions.

- Michael