AutoCAD Civil 3D 2013 - SID Files

[Anonymous]

I have tried inserting these MrSID files in two different ways. One is MAPIINSERT, and one is using the MAPCONNECT feature. While MAPIINSERT makes the image easier to manipulate (layer, clipping etc), it doesn't seem to exactly match the coordinates of my drafted items (linework, points) that are on the same coordinate system. Also, it doesn't overlay right on top of the same SID file I insert using MAPCONNECT. Can anyone shed some light on this for me? Also, is there any way to designate a layer to a SID file that is connected using MAPCONNECT? Thanks.

[Cadguru42]

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@Anonymous wrote:

I have tried inserting these MrSID files in two different ways. One is MAPIINSERT, and one is using the MAPCONNECT feature. While MAPIINSERT makes the image easier to manipulate (layer, clipping etc), it doesn't seem to exactly match the coordinates of my drafted items (linework, points) that are on the same coordinate system. Also, it doesn't overlay right on top of the same SID file I insert using MAPCONNECT. Can anyone shed some light on this for me? Also, is there any way to designate a layer to a SID file that is connected using MAPCONNECT? Thanks.

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Not sure why they aren't coming in at the same place. You might get better help in the Map group as this is more of a Map issue than C3D.

The FDO way to bring them in only loads enough of the image to match the current view and scale (unless that's changed...it's been a while since I've used it). If you zoom in, you need to refresh the image layer (on the Map Workspace), but then if you zoom out again you'll have to do it everytime. It's very annoying and why I've stuck with MAPIINSERT for so long.

Also, check to make sure that the image's units are matching the units of your coordinate system. There is a design flaw in 2013 where MAPIINSERT only reads one line of the header information to determine coordinates and units. It ignores the actual units field in the header, which can cause issues. If the image isn't off by a huge amount, perhaps it's the difference between International Feet versus US Survey Feet?

[rkmcswain]

Are you perhaps working in surface coordinates, and the images are in grid coordinates?

This is routine here, and we have to scale the images by the grid to surface scale factor (usually ±1.00013), which means we can't use FDO at all since that cannot be scaled.

[Anonymous]

My grid surface coordinates appear to match my surface coordinates. I guess I am not familiar with FDO.

[Anonymous]

I will repost in the Map Group, thanks for the direction. As far as FDO goes, I suppose I am not as familiar with it as I should be. I know that my units are correct, but I think i will do a little more research to determine that the International/US foot isn't making the difference, because it is off by only a small amount.