...
LSCM (Triangles) - Least Squares Conformal Maps is a more complex algorithm, which allows us to receive better unwrapping results. There is one important restriction for the current implementation of this algorithm, namely all facets must be triangles.
Current main unwrapping algorithm (Projection) for the TC Surface case is very simple and thus gives bad results for the many cases. For example, for the segment shown on figure 1, we will receive bad segmentation, which is shown on the figure 2. Here it is important to note, that segment from figure 1 has facets on the side part of the shoes, which are orthogonal to the facets from the base part of the shoes. That is why in this case Projection algorithm gives us bad results.
Figure 1. Segment which has practically orthogonal facets to each other.
Figure 2. Unwrapping results for the segment from fig. 1 by using Projection algorithm.
This was a motivation to add some additional more complex algorithm, which allows us to receive better unwrapping results. For this purpose we choose Least Squares Conformal Maps (LSCM) algorithm. But there is one important restriction of the current implementation of this algorithm – all facets should be triangles. But it is not very strong restriction, because practically all surfaces, which is come from the side applications has exactly triangle facets.
If user wants to use LSCM algorithm, he can do it via common UV Mapping Options dialog (see Fig.3.).
Figure 3. UV Mapping Options dialog (choosing LSCM).
At it is possible to see from the fig. 4, LSCM gives much better results (in comparison with projection, see fig. 2) for tested example.
...
For example, this segment has facets which are practically orthogonal to each other
The result is as follows with the Projection method.
However, with LSCM the following results will occur.
.
Specify the projection direction for UV parametrization
...