It is clear that transforms are needed to "reflect" points from one coordinate system to another. From what I can remember, when a point is selected from a part in an assembly model it needs to be transformed into the assembly model (or something like this). I have not been able to find a concise description of the different coordinate systems and how they are related to each other. Hopefully someone will be able to explain this. Is there a good article available?

A related question is a description of what (not how) the transform functions do? In theory transforms can rotate and translate points but very little information is actually needed for the transform functions. Why is this? Is it because it is built into the transforms to "translate" from the part models to the assembly model, or what? If there is a need to translate in the other directions, is the answer really as simple as the inverse of the transform function? If so, what does that look like?

Thank you in advance.

Ed

Hi Edwin

Each environment (sketch, Drawing, Model, Assembly ) has its own coordinate system. Transformation is like a math coefficient which you can get from API and use to multiply on coordinates.

So if needed to measure the distance between two entities from the same environments then they have the the same coordinate system and transformation is not needed.

If the entities are located in assembly but belong to different components then we should get the coefficient for the first component COEFF_1 and multiply to the entity of the first component. Then get the coefficient for the second component COEFF_2 and multiply to the entity of the second component. Now these multiplied entities have the same coordinate system (the same as active assembly) and we can get the correct distance between them and also between each component and some assembly point (like center of mass )

More info on how the transformation is calculate could be found everywhere (e.g. http://web.iitd.ac.in/~hegde/cad/lecture/L6_3dtrans.pdf )

Hope this can help as a start

Regards

Viktor