Let’s say that you need to drape an imagery in Civil 3D over a surface. First of all you will need an aerial image that you need to either align or have it georeferenced. For the most of the cases you will have a georeferenced image that comes into a jpeg, mrsid, geotiff or other image format that includes a world file that defines their position in space.
If you have the image, I hope that you have it in the same coordinate system as the drawing that you need to bring it in. Let’s take the simple case where everything matches as coordinates. In order to bring it in Civil 3D and make use of the world file you will have to use the map command called mapiinsert ( notice the two “ii” ). From the dialog box, please select the image and click open.
In the next dialog box, look at the settings to make sure you have the right units and hit ok.
The image will be inserted and if everything worked fine it will be in the right place.
In order to drape the image on the surface you will select the surface first and you will look at the contextual ribbon where you will find the option of Drape Image.
When you hit the drape image you will find yourself at this next dialog box.
Let me explain what is it in the dialog box and why you need to pay attention to it for both the objectviewer and model space display.
First, you have the image and it should match the name of the image you just inserted. Then you have the surface selection and this should be automatically selected as the surface you need to drape the image unto. Then pay attention to the last item. The last item is the Render Material Name. When you drape an image, Civil 3D creates it as a material and applies it to the surface. This material will be available in the list of materials saved in the dwg. Click OK and you are done.
Now there are two options to view the draping: ObjectViewer ( which is a temporary view, since you cannot do anything else while you view the object ) and the 3D Model space View.
If we want to see the drape result in Object Viewer, select the surface you just draped the surface unto and then right click and from the drop down list select Object Viewer. Once in Object Viewer select the Realistic Mode View and rotate the surface from the top view to an isometric view and you will see the result.
Now in order to view the same surface in a permanent display mode we will have to show it in a 3D Model Space View. In order to do that you can either change your display to an isometric view in the current viewport, or change the viewport display to a splitted screen viewport so that in one place you will have the top view and the other viewport you will have the 3D view. In order to do that go to the Ribbon and select from the view menu the two viewports configuration :
Once you got that one done you will have two identical viewports with the Top View and the wireframe display. Now you can change the right view to an isometric view and the realistic display mode as shown below:
Note. In order to have your surface displayed in 3D mode you will have to get the triangles displayed in the Model tab of the surface style for the surface.
This is all. Now do you remember when I mentioned the part of the material? If your surface does not display the draped image in the Model Space 3D view, then you most likely forgot to set the rendering material to the one that was created when you draped the image. This set is done by selecting the surface and accessing its civil 3D properties and setting it in the Render Material Box.
If you have issues following the text and the images, see the attached screencast for the workflow.
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