Rotate face in ruby

ipomea

Hello !

I am a beginner with ruby, and I want to rotate a face, and retrieve the new face
I have the following code:

` model = Sketchup.active_model # Open model
entities = model.entities # All entities in model
selection = model.selection # Current selection

pt1 = [x,y,0]
pt2 = [x1,y1,0]
pt3 = [x1,y1,h]
pt4 = [x,y,h]
fc = entities.add_face pt1,pt2,pt3,pt4,pt1

tr = Geom::Transformation.rotation ptm,vector,angle
bas1 = entities.transform_entities(tr,fc)`

this returns a status, what I want is the face after rotation. If I try anithing else, I always end up with an error

Is the rotated face still fc or is it an other one and how can I find the new one ?

TIG

You didn't show us how you get/set
ptm,vector,angle
but let's assume they are setup properly, because you'd get worse errors otherwise

The face ' fc' should remain a reference to the face even after it's transformed: however, it it lands on top of or overlapping another pre-existing face you might loose the reference, or find it refers to an unexpected face...
If you are doing the transformations of a limited number of faces within a container context [ some_group.entities etc] then you have more control of what's there already, compared with the model.entities...
If you want real comfort consider adding a temp-group and putting your new face inside that:
**gp = entities.add_group()** fc = **gp.**entities.add_face(pt1,pt2,pt3,pt4)
[Note: there's no need to repeat pt1 at the end - unlike with ' add_edges()' if you want all 4 edges created]
Then you can transform the temp-group with ' gp.transform!(tr)'... OR transform the entities inside the temp-group:
gp.entities.transform_entities(tr, gp.entities.to_a)
Although, because the temp-group is unlikely to share the same ORIGIN, you would then need to consider the point about which you are rotating [ ptm], relatively to the gp.transformation.origin - Hint: after the face is created inside gp use ptm.offset!(gp.transformation.origin.vector_to(ptm))... THEN define the tr transformation using the corrected ptm
At this point ' fc' is still the same face, because it cannot have interacted with other geometry...
After doing whatever it is you are doing explode the temp-group gp.explode ...

ipomea

Thank you very much. This has really been helpful. It was OK the first time I tried

This is the end result: