Project shadow of object onto surface?

[hobbs101]

Hi. I need to project the 'shadow' of an object from a point source of light onto a flat surface. This object is a cone, but could be more complex.

Any thoughts on how this might be achieved?

Hobbs101
Mechanical Design Engineer

 

[Sparweb]

I wouldn't use Inventor for that!

Seriously... why? This is a job for 3Dstudio or some kind of Adobe animation product.

All I can think of is to create a point ( the light source) and a plane (the flat surface for the shadow).
Then create a zillion construction lines from the point, intersecting the relevant edges of the cone.
Then on the plane, create a sketch based on the intersection of the lines with the plane.

This would be very time-consuming and it would "break" every time you moved either the cone, the point, or the plane.


STF

 

[hobbs101]

The reason I need to do this is because I'm designing a lead mask for an x-ray machine. The mask sits behind the cone object. Ideally the mask would be a perfect cutout, blocking all the rays (emitted from a point source) outside the perimeter of the object.

I know there will be other challenges in producing such a mask, e.g. how will it be machined!, but at least being able to create it within CAD will be a starting point.

Hobbs101
Mechanical Design Engineer

 

[Sparweb]

OK, I thought it was some 3d graphics presentation you were looking for.
So the mask blocks the rays that have been emitted but have not passed through the subject.
If the subject can move, then you will need some way to adapt the mask model parametrically, with respect to the orientation of the cone.
After giving it some thought, I believe Inventor can create an ellipse constrained to 3 points, which would allow you to create the projection of the cone with just a small number of construction lines.

Perhaps the mask should be close to the isotope container. It would require much less lead. Or would that cause significant diffraction?


STF