Imported map images: scaling and updates

T6A5

Hi all,

I have a couple of questions about importing external image files into CC3+.

The first one concerns what happens if I import an external image file, and later update that file (there is a city map I have been working on since my pre-CC3+ days that is not yet finished, but I would like to begin working on a transport network for the city). I have tested an import of an external file using the 'Store the file's path relative to current drawing' option, and when I make an edit to that file in paint.net, and reload CC3+, it shows me the updates in the file accordingly. Is this something universally true, or is there any import setting that does not update external files I should avoid tinkering with?

My other question concerns re-importing an image file. Last year, I imported that city map into the national level map I was working on, to be able to outline the city boundaries, railway lines, and highways that passed through. I found that having this link to this very large image file caused CC3+ to lag, so after I was done, I deleted the image file from CC3+. If I ever needed to import it again, would there be a way for me to rescale it to exactly the same size as it was before? Or would I have to just play it by ear... err.. eye?

Thanks in advance!

Monsen

Posted By: T6A5The first one concerns what happens if I import an external image file, and later update that file (there is a city map I have been working on since my pre-CC3+ days that is not yet finished, but I would like to begin working on a transport network for the city). I have tested an import of an external file using the 'Store the file's path relative to current drawing' option, and when I make an edit to that file in paint.net, and reload CC3+, it shows me the updates in the file accordingly. Is this something universally true, or is there any import setting that does not update external files I should avoid tinkering with?

CC3+ always refers to the file on disk, so it will always be updated with any changes you make. This also means that once imported, you should never rename/move/delete the file, as this will cause CC3+ to not find it any more.

My other question concerns re-importing an image file. Last year, I imported that city map into the national level map I was working on, to be able to outline the city boundaries, railway lines, and highways that passed through. I found that having this link to this very large image file caused CC3+ to lag, so after I was done, I deleted the image file from CC3+. If I ever needed to import it again, would there be a way for me to rescale it to exactly the same size as it was before? Or would I have to just play it by ear... err.. eye?

You can do a few measurements to set the size exactly:
1. Import the file again, just approximate the scale for now
2. Use the Info-> distance tool to measure some things in your map that also appear in the image. Note the distance
3. Then, use the distance tool again to measure the same location in your image.
4. Then, use non-visual scale (right click the scale button to find this option) on the image. When asked for the scale factor, just input the number measured in 2 divided by the number measured in 3. (Note that you can just enter the calculation on the command line in CC3+, for example if the numbers are 10.3467 and 13.6537, just enter it as 10.3467/13.6537 on the command line when CC3+ ask for the scale factor)
5. Finally, move the image so it lines up properly

Note that the link to the image shouldn't affect CC3+ performance if you keep it on a hidden layer or sheet when not using it.

T6A5

Fantastic! Thank you so much for your help.

EDIT: One other question I have is about whether is a size limit, whether physical or file, to a file that can be imported into CC3+? I'm attempting to insert the street map file as we speak, but I'm having no success doing so. I thought at first that it might have been the physical size of the file as inserting a random photograph from that same folder gives me no problems at all, but then I remembered I was able to successfully do this last year so that can't be it. However, I have worked on the map in the year or so since I last imported it into CC3+ and presumably the file size has gone up. Could that be a factor in why I'm not able to get the file in? For reference, it's currently 21.2 MB.

JimP

You can insert by reference, that should make no difference to the file size as its not inserting the file itself.

T6A5

In the end, it turns out that the issue with the map was that it was around 20k pixels on the larger side, and apparently CC3+ is not equipped to handle such files. I have made a second, scaled down version of the iamge that I will update every time I make a change to bus infrastructure in the city, that's about 70% of its size and about 15k pixels on the larger side, which works fine.