UV-Mapping a Humanoid Figure, Part 1.
Wings3d has some very good UV mapping features, but never less, it can be tricky to get a really good mapping.
So, what is a good mapping? A good mapping has minimal stretching and a minimum of seams. The seams and the stretching will ideally be located in regions not often seen. For creatures, the mapping with the minimum of seams is a pelt like map. Some experience in texturing various objects will make it easier to get a idea what kind of map will make texturing easier.
The unwrap feature in AutoUV is great for this kind of things, but can not handle the whole map at once. Instead we have to do it in pieces and late stitch them back together.
To unwrap the UV Map, we first have to define cut lines to separate the mesh in pieces that are unwrapped separately. These pieces are called charts.
The cuts are defined in the AutoUV window, but I prefer to prepare them in the geometry window. I use edges set to "hard" to mark them for cutting (edges->hardness->hard).
The pieces I cut for the body are: Front, back, arms including shoulders, legs, back of feet, top of feet, sole including downside of toes, top of each toe, palm, back of hand, inside and outside of each finger and in this case the genitals.
The finger- and toenails are separate modelled pieces and are cut in front and back.
The head is cut in face and back. The nostrils and eye cavities are cut out, as well as the inner mouth. It is important to map the convex areas separately. The front and the back oft the ears are two more charts.
The teeth, eyes and lashes are modelled as separate objects in this figure. I will map them later.
When all necessary edges are marked, select I them (select->by->hard edges), and create a group for them (select->new group). Afterwards, I set them back to soft (edges->hardness->soft).
Now I change into body mode and select the figure and select UV Mapping in the context menu. This opens the AutoUV window.
I set the selection mode in AutoUV to edges. Next I activate the stored group in the Geometry Window (Select-> select group). This will also select the edges in AutoUV. In the context menu of AutoUV I use "mark for cut" and then select "continue" from this menu and followed by "unwrap".
After a short wait, the result will be something similar to the next picture. Each chart should be unwrapped flat and evenly.
If some of the charts curl up on one end, you need to delete all charts in the AutoUV window (select in body mode and choice delete from the context menu). Close AutoUV and change your cutting edges. Try to cut the problematic charts in two. Then repeat the unwrapping.
I once run in the problem that AutoUV exited the unwrapping with the message "Numeric problem while unwrapping chart". The offending chart will be selected after the error. I fixed it by tighten the mesh by a minuscule amount, to move each vertex a little bit.
When the charts look good, I close AutoUV and open the Outliner window (Window-Outliner). In the context menu of outliner I choose "Image". That gets me to a dialog where I set width and high to 512 and Pattern to Checkerboard. There should be a material with a name consisting of the name of the object and the postfix "_auv". In the outliner I drag the image on this material and apply it as a diffuse texture.
The checkerboard should now show up on the figure. If not, make sure that "Show textures" is selected (View-> Show textures).
Ideally, the pattern should be the same size and perfect square on all parts of the figure, but in this stage, there will be some distortion. In this example, we see some heavy distortion on the breast, for example.
To the next part.