Hi everyone,

I am working on the scrip of a component from LadyBug and there is things that I don’t understand becaune I have never used Python and I started using Grasshopper 2 weeks ago. This is a part of the script :

intNormal = cleanBrep.ClosestPoint(intPts[-1], sc.doc.ModelAbsoluteTolerance)[5]

lastVector = rc.Geometry.Vector3d(ptList[-2] - ptList[-1]

lastVector.Unitize()

crossProductNormal = rc.Geometry.Vector3d.CrossProduct(intNormal, lastVector)

plane = rc.Geometry.Plane(intPts[-1], intNormal, crossProductNormal)

mirrorT = rc.Geometry.Transform.Mirror(intPts[-1], plane.Normal)

lastRay = rc.Geometry.Line(intPts[-1], lastBounceLen * lastVector).ToNurbsCurve()

lastRay.Transform(mirrorT)

So the code traces ray and the specular reflexion on a Brep.

I don’t understand what mirrorT is actually and what Geometry.Transform.Mirror does.

Thank you so much for your help !