Friday, July 11, 2014

Draping Your AutoCAD Drawing in InfraWorks

So you want to see your AutoCAD (or Civil 3D, or whatever AutoCAD-based product you have) drawing in InfraWorks. You've tried attaching a DWG as a data source but that didn't go quite like you expected, did it? InfraWorks tries to be really smart in that case and convert all of your AutoCAD entities (lines, arcs, circles, etc.) into InfraWorks entities (roads, water areas, buildings, coverages, etc.). What if you just want to see your drawing, as it its, no conversion, draped over your InfraWorks model like this?
It can be done, and the product that is key in doing it might surprise you. Enter: Raster Design.

You can try this yourself if you've got Civil 3D and the latest version of InfraWorks. I opened one of the Civil 3D tutorial files, one that had a coordinate system assigned so that I knew how to georeference it. I dressed up the colors a bit and made it look good. The file is Parcel-1A if you want to try it yourself.
Next, I used the Raster Tools tab (Raster Design) to create a new image.
I used the default settings but you can tinker with the settings here to get the perfect resolution and image size. I used the Pick button to set the extents of the image to match the part of the drawing I want to show in InfraWorks. I also used the True Color option so that the colors of the image will match the colors I see on screen.
Now I have a blank image. I use the Merge Vector command to add the AutoCAD entities into my newly created image. Piece of cake: just pick the objects you want to include and tell the command whether you want to delete the original entities or keep them. I kept mine, there was no reason to delete them.
In the drawing, it may look like nothing has happened because a color copy of what you see on screen has been generated in raster form. Now it's time create a data source that InfraWorks will understand. I'll use the Image Export command on the Raster Tools ribbon.

For my example I used TIFF, Uncompressed, Tiled, with a World File (that's important for georeferencing). I took note that the coordinate system of my drawing is NH83.

Now it's time to go into InfraWorks. I created a model of the area using the Model Builder preview. How did I know where I was? I used the GEOMAP command to show me an aerial/roads hybrid in Civil 3D, noted some key roads, and found the same location in Model Builder. Then I added my file as a raster data source. I had to tell it the NH83 coordinate system, and then Voila! My AutoCAD drawing draped in my InfraWorks model.
So there you have it folks - an AutoCAD DWG shown in InfraWorks! What's that?....The black area?...Ah, we've got something for that too. I'll go back into the Data Source Configuration dialog to the Raster tab. There I find a Color Mask setting and when I click the ellipsis button I actually get a Pick Screen Color button. Using this I could tell InfraWorks to make the black transparent.

Oh, yeah...that's what I'm talkin' about! This is what I had in my mind when I thought about importing my AutoCAD drawing in InfraWorks.


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  4. The masking of the raster image doesn't work for me. Not sure what step I have missed.

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  6. how do you tell IF to make the black transparent?

  7. when you render the image displays black area where the raster overlaps. Is there a way around it?

  8. When selecting the color as the background mask/transparency it sort of works. The black area turns to a pale purplish color. Not really transparent.

    Any ideas on how to correct that?

    1. I fix that by setting RGB+ALPHA on band mapping..

  9. Eric, This workflow worked great for me. One note I can add is that before you run the VectorMerge (IVMERGE) command, take a look at the Raster Pens settings (RPENS). There you will be able to set the pixel width for the various ACAD Colors. This may help crisp up the line work keeping it from making the vector lines thick and chunky.

  10. This is a very informative article. And it's written so that people that don't use CAD can begin to understand some of the complexities that we face as CAD & Data Admins.

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  12. Eric, again you save my life!! ehehhe
    Just to use de color mask


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