Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Project shadow of object onto surface?

Project shadow of object onto surface?

Project shadow of object onto surface?

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?

Mechanical Design Engineer

RE: Project shadow of object onto surface?

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.


RE: Project shadow of object onto surface?

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.

Mechanical Design Engineer

RE: Project shadow of object onto surface?

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?


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close