Optics: real images vs virtual images and focus points

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Embedded figures are used here to reinforce understanding:

The block Image gets mutually exclusive value properties isReal:Boolean and isVirtual:Boolean, where the main image:OpticalImage of the OpticalTelescope has a constraint {isReal} and the image viewedImage:OpticalImage has a constraint {isVirtual} (this will be justified by some later snippets).

The following new elements in the model help tie together the observed object, the light rays, and the image. From the point of view of an «optical» system an observed Object is composed of one or more point:ObjectLightPoint[1..*], each of which may be associated with one or more lightRay:LightRay[1..*]. An Image is now defined as having a 1-to-1 Association with an Object (so 'object' is not used here in the sense of many "objects" in a view, i.e. it means an the entire image view, not a star in an image of a cluster).

We are told that:

So OpticalImage has one or more focusPoint:FocusPoint[1..*], which in turn has one or more lightRay:LightRay[1..*]. There are some constraints in a concise "mock OCL" (without full use of OCL forAll or forAny) to say that the lightPoint (on the object) of a lightRay of a FocusPoint must be the same as that of the FocusPoint, and that the 'object' of the OpticalImage must be the same as that of the 'lightPoint' of every 'focusPoint'.

We are warned that:

This is for now represented by a reference property blurCircle:BlurCircle on FocusPoint.

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