Inserting a circular raster image

If you are a long time, experienced user of AutoCAD, how many times have you stepped back and looked at the program from a novice point of view? Think about some of the tasks that seem trivial to you and then consider how you might perform them if you were new to AutoCAD.

I ran into this case recently, when the question was brought up "How to bring in a raster image in the shape of a circle?" Easy, right? But think about being a new AutoCAD user and not knowing about the various commands used to do this, or even how to go about finding them. I have not search Help, but I doubt this particular task could be found in the User's Guide.

On to the problem.

  • First off, you have to insert the raster image itself. The quickest way is to enter the ._ImageAttach command at the command prompt. If you insist on using the Ribbon, then look for "Insert" on the Reference panel of the Insert tab. Select the raster image and then place it in the drawing at the desired location.

  • Next, you want to change the shape of the image to a circle. How do you do this? Well, if you did use the Ribbon, you might see the word "Clip" right next to "Insert". Let's try that. It asks you for the image, then asks you to specify a new boundary, but wait! It only allows you to draw a polygon or rectangle? So how do you clip to a circle? Let's try drawing a circle first and then running the Clip command.... No, it will not allow you to select the circle... Now what? This is where a novice might get stumped. At this point, there are two options.

    • There is an Express Tools command (Express Tools Tab, Modify Panel, Extended Clip) named ClipIt. This will allow you to select a circle, but if you are a new user, how would you know to look there?
    • The other option requires you to be a bit creative. Since the Clip command allows you to draw a polygon, maybe it will allow you to select an existing one. It does. Now wouldn't a 200 sided polygon pretty much resemble a circle? So how do you draw a 200 sided polygon without having to do it manually? If you poke around the Draw panel on the Home tab, you should find the Polygon command. Select it and then draw a 200 sided polygon. You can adjust this number as required.
  • Now you have the raster image, and a "circle" (actually a multi-sided polygon)
  • Run the Clip command again, and use the "S" option, to Select an existing polygon and then finish clipping the image.

I have included a short animation of this process below. Due to size limitations, I used the command line for all command entry.

By the way, you might think the Express Tools command ClipIt would be the better tool since it allows you to select a circle, but the end result is the same since it actually converts the circle to a polygon and used the polygon to clip the image.

Comments

Nice Reading. Thanks.

The way that I have always done this is to draw a circle, then draw a line, trim the circle in half, mirror the Arc, then pedit them together. You can now use this as the clipping boundary and with raster images and PDFs thi seems to work faster than a 200 sided polygon does.

Seriously? The animation in this post is in real time. I'm creating the polygon in about 5 seconds. I don't see how you can draw a circle, draw a line, trim the circle, mirror the arc and pedit it all back together in 5 seconds.

I'm not saying that is not a valid method, because it will work just as good - but I can't see how it is faster.

Thanks for the comment - just goes to show there are many ways to end up with the same result.

I wonder if the "work faster" comment is related to the feel of the system related to regens.

Does the number of segments in the clipping polyline affect redraw / regen performance?

 


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