Primitives are parametric meshes that depends only on their 'parameters' value. The associated mesh structures (vertices and triangles) are mainly used for display and may be regenerated each time a parameter of the primitive changes (notably it's 'precision' parameter). So you can of course modify the vertices position, but you may lose this modification in an unpredictable way (each time the primitive is cloned, saved, or each time it's 'precision' parameter is changed, etc.).
The best way to do what you want is to 'duplicate' the primitive with new parameters:
Code: Select all
ccPlane* newPlane = new ccPlane(newXWidth,newYWidth,&pPlane->getTransformation());
After that, you'll have to restore display parameters yourself (plane color, stippling, etc.).
P.S. : please ask this kind of questions in the 'Developer > qCC' thread