11 replies to this topic

[MapMedia]

Here is an Illustrator screen shot of inner buffers.

Any ideas how they were done, because they were done on (apparently) Bezier curves?

* I tried Arcmap to Ai as DXF, simplify polyline and back to Arcmap, but Arcmap won't accept bezier curves.
* Mapublisher's buffer simply creates a line stroke using pts based on a calculation of the projected units.
* AI's stepped blend is not a proper buffer algorithm.

[rudy]

Chris -

I'm not sure what you are asking. I don't know about Illustrator but I suspect that it works like Corel Draw. Are you saying that the image you provided was NOT done in Illustrator? But the image is taken from Illustrator . . . but the buffer is in ArcMap? I don't quite understand what the question is.

[benbakelaar]

I think that's the answer. The buffers were done in ArcMap, not Illustrator. Are you trying to figure out how to accomplish the same graphic effect using Illustrator only?

[MapMedia]

Backing up a little more:

I have a map showing inner buffers and am trying to replicate this effect for a client.

What I see in the map (its a PDF so I can tease it apart a little in AI): buffers created from bezier curves.
You can't have bezier curves in ArcGIS 9.2. I did create stepped inner buffers in ArcGIS on simplified polygons,
and exported to AI, but the linework still needs bezier curve generalization. Doing this in AI warps the whole thing.

So, in short, I am asking if anyone has ideas on how to create the example effect (note: bezier curves and buffer areas).

Thanks!

[rudy]

I don't have ArcMap in front of me here but could you export the polygons to Illustrator, generalize / add bezier curves, do the blend thing, then import it as a graphic in ArcMap? Or does ArcMap dislike bezier curves completely (even as graphics)?

[Martin Gamache]

Have you tried to use offset path with a negative value, it seems to work OK, not great but OK.

Just wondering why you need bezier curves?

I can get it to work with a 9pt stroke and a -0.12 offset. I then need to adjust the colors manually but it's fairly easy in HSB mode.

Freehand was able to do this sort of thing fairly well too if I remember correctly.

[MapMedia]

Offset path with negative value can produce the inner boundary from which to create a stepped blend.
Bezier curves are produced when using the path/simplify function in AI - I typically simplify most all linework, even
if its only 99-98%. (please correct if I am mistaken).

For this specific project there are just way too many contours to make, so I am looking for new ideas/methods. Hopefully
there is an AI script out there with my name on it. If there is I will post the link in this thread.

Thanks all!!

[Unit Seven]

How about just adding extra strokes to the object style? Set all strokes to inside and get progressively larger - see screen dump below.

To ease changing the colours you could make a graphic style and set tints of a spot colour to the strokes.
Apply the style to the next object, copy the object to another document and edit the spot colour (and change the name) so that it changes all stokes at once. Then paste this back into the new document. This Would prob work just as well with global colours which would be a better practice than spots.

Attached Files

•  inner_buffers.png   106.46K   94 downloads

[MapMedia]

And the winner is...Thank you, Sam. That works well.
I had just started implementing this using stroke style, but the align inside was the final trick. Screen shot was very helpful.

[Nick Springer]

This is the same technique I use to create an old school coastline effect. I use alternating black (or gray) and white lines of increasing stroke widths.
 stroke_effects.gif   398.46K   171 downloads

[MapMedia]

That is excellent Nick - what a great effect. Do you recall the name of the Lake Huron font?

[Nick Springer]

I have a bunch, so off the top of my head I think that one is "Old Claude"