Creating a Callout

I would like to create numeric callouts for a plan. Such a callout might be a circle with a number in it. I need to be able to scale the callouts such that all in the plan scale uniformly.

I am essentially looking for a block with a where each instance of the block has a number associated with it (that in a few cases could be duplicated).

I was wondering if there is some relatively simple way of doing this.

You have three options: dots, blocks, and leaders. Most Rhino users use dots. They are made by Dot command. Blocks use attributes made by ConvertTextToBlockAttribute command. Leaders are made by Leader command.

This might be possible to script. But your description is not very clear. Can you give some image examples of what you have in mind?


It appears the dot might suffice for my purposes. I was hoping for some kind of automatic numbering but this should work.

Except that the dots don’t have a fixed size. Is there anyway to keep them from scaling when I zoom?

In the alternative, is there some descriptive instruction on how to use ConvertTextToBlockAttribute? The help file in isolation does not give a good starting point.

Hi -

That is not possible, no.

That command is used as one of the steps of making an “Attributed Block”. From Rhino 7, it is possible to store a key-value pair on an instance of a block definition so that the value can vary between instances of the same block definition.

For your callout example, you make a text object with a number and run the command on that text object. You are asked for a key name, an optional prompt, and an optional default value.

In the next step, you select the text object and the circle and run Block on those. You name the block definition and are then prompted to provide a value for that instance. You then have your first instance of that block - likely a “1” with a circle around it.

To create your second callout, you run Insert, select the block definition, give it a value and place it in your document.

The thing that is missing for this feature to work as a callout, is that there tends to be a line from the circle to the object that is referred to. You can include a line in your block definition but that will then always be of the same length and going in the same direction.

In my immediate case, the callouts are going at the exact point of interest, so the lack of a leader is not a problem. If would be nice to be able to have the block size itself around the text.

Hi -

That would require some kind of “smart block” - I’ve added the example to item RH-57711.
It doesn’t sound like you are talking about a circle, though. For the sake of completion, and as already been requested by Gijs, please post a picture of what a typical callout looks like in your field of work.

This is for a book so I am open. I need something that is both subtle and stands out. The dot looked pretty good but for the resizing.

Feature Request:

When prompting for the field value after inserting the block, the input text box should get focus.