This provides a straightforward way to convert an attribute from one class to another. For example, a point attribute can be converted to a primitive attribute, using any one of a number of different merge methods.
For index attributes, the merge methods treat the attribute as a string. Average will perform median, sum will perform concatenation, and the other numeric methods will just resort to First Match.
For attributes with multiple components (such as vector), each merge is done on each component independently.
This is the name of the attribute in the source class. Eg:
will pick color. This can also be a pattern or space separated list of
attributes, such as
This is the class which the attribute starts in. It can be one of point, primitive, detail, or vertex.
This is the class to which the attribute should be promoted. It must be different than Original Class or a warning is raised and nothing is done.
Whenever there is more than one attribute in the original class which matches a single entity in the new class, some method must be used to determine the new value. For example, if converting from point attribute to primitive attribute, there will be many points corresponding to a single polygon.
Picks the largest match.
Picks the smallest match.
The mean, or the sum of all matches divided by the number of matches.
The most common match. If there is more than one most common, it will be the minimum of the most common.
The middle of the matches. If there is an even number of elements, it is the higher of the two possible middles.
All of the matches added together.
Sum of Squares
All of the matches squared, and then added together.
Root Mean Square
The square root of the average of the squares of all the matches.
The first valid match. For promoting points to primitives, this would be the point of the first vertex in the primitive.
The last valid match. For promoting points to primitives, this would be the point of the last vertex in the primitive.
Change New Name
If not set, the new attribute name will match the original name.
The new name for the attribute if Change New Name is set.
If the source is a pattern, this new name should be a pattern that can
expand to the same length. Glob-style renaming is done, so if the
matching pattern is
instance* and the new name is
instancepoint would be promoted into
If set, the original attribute is deleted after promotion. Note that in some cases, such as promoting a vertex attribute to a point attribute of the same name, the original attribute will always be deleted. To avoid this, rename the attribute when promoting.