Where is Featurescript Environment/Reference System Documented?

peter_morris

I may have completely missed something, but I cant seem to find a description of the Featurescript environment.  By this I don't mean the programming environment is documented; I mean the drawing space - what are the basic parameters, what are each element of a Vector referring to for example, if I identify and edge i can return the adjacent vertices, but how can I get only 1 of the 2? How do I know the position of that vertex.

I'm sure these are simple ideas and concepts and they are probably simply common sense to those experienced in 3D CAD/Featurescript, but I'm just starting out and while I'm slowly fathoming it out through trial and error it would be so much simpler if there was a short tutorial or documented description.

If I've missed it please tell me where to look.

Many thanks for a great programme.

lana

Top plane is Z = 0, Front plane is Y = 0, Right plane is X = 0, origin is (0, 0, 0)

NeilCooke

Right hand rule. Positive rotation around +Z is counterclockwise. 

Jake_Rosenfeld

Hi Peter,

Have you looked through https://cad.onshape.com/FsDoc/ ? It sounds like you have the basics down, but maybe skimming through the FeatureScript tutorials could help.  Additionally the Standard Library documentation can be very helpful once you get a better grasp of the language.  The 'Language Reference' and 'FeatureScript Guide' sections on the sidebar are also very helpful.

As a more specific answer to your question, FeatureScript references geometry in terms of 'Query's.  If you end up with a Query that refers to two vertices, you could do 'var oneVertex = qNthElement(twoVerticesQuery, 0)' to get the first vertex.  To find the location of that vertex you can use 'var location = evVertexPoint(context, {"vertex" : oneVertex} )'.  location will then be a vector where the 0, 1, and 2 indices refer to the x, y, and z coordinates respectively.

https://cad.onshape.com/FsDoc/library.html#qNthElement-Query-number
https://cad.onshape.com/FsDoc/library.html#evVertexPoint-Context-map

peter_morris

Hi Jake, many thanks for the prompt reply.  I have been working through the documentation in some detail.  What I think I'm lacking is an understanding of the framework in which Onshape operates.  I think I have the idea of sketches leading to features, but perhaps its the more fundamental foundations that i'm missing - its highly likely its so simple it doesnt seem worth explaining.  I understand the concept of queries and, I think, evaluation, but what is lacking is a description of the space in which they operate.  For example, how do x, y and z, coordinates relate to the planes Top, Front and Right; perhaps: x & y axis bound the Top Plane, with positive Z as the 'up' normal, what direction is rotation measured, how do dimensions relate to positions.

I hope that makes a little more sense of my question.

Regards

NeilCooke

XYZ relate to the coordinate system in the top right corner of the graphics area. 

lana

Top plane is Z = 0, Front plane is Y = 0, Right plane is X = 0, origin is (0, 0, 0)

peter_morris

Hi Iana,

Many thanks.  Can you say which direction is a positive rotation?  Traditionally Clockwise would be a negative change in angle - so would be good to know how Onshape treats it.

NeilCooke

Right hand rule. Positive rotation around +Z is counterclockwise. 

peter_morris

Many thanks - the prompt response is much appreciated.