Problem

When importing a DXF or shapefile as a background, it does not show up in the model, even when pressing zoom extents. Or, the background appears far from the model elements.

Solution

If the drawing pane appears blank when using zoom extents, this could be due to some extra linework being located far away from the main drawing. When you click the zoom extents button the model will zoom very far out in order to display everything. After zooming extents, press CTRL+A to select all, and you may notice a small red dot appear, indicating where the model elements are located. The DXF linework causing the problem in question will be located in the far opposite corner of the drawing pane. In this case, try opening the file in AutoCAD or MicroStation and try the same thing. If you locate extraneous linework far away, delete it from the drawing, re-save the DXF (you can also try an older DXF format such as 2000) and try inserting as a background in the OpenFlows product.

Also, confirm that the correct units were used when inserting the background. You can right click on the background layer and choose "edit" to change this. Similarly if the model was built using ModelBuilder, check the "coordinate unit" that was selected in the first ModelBuilder step. Open the ModelBuilder manager and check if the definition is still present from when the model was built, so that you can check this. (see similar discussion here)

This could also occur if your model is located in a different place (based on the X/Y coordinates). Try going to View > Zoom > Zoom Center and zooming to a coordinate that you know is within the drawing. You could also bring the background file into a blank drawing and locate the center coordinates of the drawing that way. The coordinates in the standalone version of the software are shown in the location in the screen shot below. Once the coordinates are located you can use the Edit > 'Select All' feature or CTRL + A to select all the elements in your model and drag the model file over to a location of the background.  

If the units are correct but the DXF is not showing as a background:

• Try saving and reopening the model, or opening the DXF in a program such as AutoCAD or MicroStation to check for problems. When checking for problems with the file in AutoCAD or Microstation check for unsupported entities such as Mtext, Arc's, etc... They will not show up and will need to be converted to a single line text and regular polylines.
• If your CAD drawing has data in multiple layers, try placing all entities on one layer, then re-save and try again.

If the model and DXF have different units for the same location, the DXF may be in different coordinate systems / spatial references. Open the DXF in another application like MicroStation or AutoCAD, locate a specific landmark like a tank and note the coordinates (and units) seen in that external application. Then, locate the same spot or element in the hydraulic model and check its coordinates. If they are different, then the model may need to be reprojected or in some cases you may be able to simply select all elements (draw a selection box around the whole model or press CTRL+A) and drag/drop to the correct location.

If the model was built from a GIS source, it is possible that the GIS source was in a different spatial reference as the DXF and you may need to re-import the data via ModelBuilder. Or, you may be able to use ModelBuilder to "Update existing elements" if there is still matching IDs based on the selected Key field, in order to update just the geometry and "pull" the model data back to the correct location.

See Also

Text is not displaying in my DXF background