Image Draping in GEMS

Have you ever wanted to get a photo-realistic view of your solids and surfaces?

Geologists, Mining Engineers or Surveyors looking to do this can use the Image Registration Editor in GEOVIA GEMS to drape images on to solids or surfaces.

1.  First, load the triangulation you wish to use. In this example, we will be using a surface of an open pit. To make the image registration process easier, it is recommended that you have the 2D view set in GEMS.

2. Before you invoke the command, save the image you wish to use for draping in a logical location, for example, create a folder in your GEMS Project folder named ‘Images’ and save the image there.

For surfaces, it is ideal to use photos that have been taken directly above the object, such as a satellite photo for the best results.

Tip: If you are unable to obtain a photo with a suitable image resolution, use Google Earth to generate an aerial satellite image of your mine area and screen shot this instead.

However, the image draping tool in GEMS is pretty powerful and can use images that are not perfect – the example image that we will use today was taken of an open pit from a flyby in a light aircraft! Just remember if you use this type of image, parts of the draped image may look distorted when viewed in 3D. Using an image taken directly above the mine area will produce little to no distortion.

3. Now that you have your image located in an easy-to-find location, position the view of your triangulation centrally in your viewing area and consider showing it rendered (i.e. not wireframed). This may be easier when locating reference points in the Image Registration Editor.

4. Now, select Tools > Image Registration Editor.

5. Next, a dialog box will pop up. Select the image you wish to use. Please note that you must choose the file type option to be Raster Images. Later on, if you wish to change any of the registration points, you can open the GEMS Registration Files.

6. Once you have selected the image, the GEMS window will change to the Image Registration window. If your image view is zoomed in, you can Right Click and choose Fit in Window.

Note the position of the triangulation. It is centrally positioned and can be fully seen in the window. This is why you need to position it first in GEMS as I described above.

7. Next, look for features on the image that you can also identify on the triangulation. Once you have located a feature, left click on the feature on the image, then left click on the same feature on the triangulation. Repeat as necessary. As you click on the reference points, the empty window beneath the images will start to populate with details of the reference points.

Note: The more reference points you have, the better and more complex the triangulation will be. Simple triangulations will require just a few reference points (an absolute minimum would be 3).

Once you have located all the reference points your window will look something like the below.

8. To close and return to GEMS, first select File > Save As and create your GEMS Image Registration file. It is important that this file must reside in the same folder as the image you have used for draping! The file extension for this file type is *.RIMG.

9. Back in GEMS, all you will have to do is to link GEMS to your Image Registration file. To do this we need to call up the Properties of the triangulation, either by hovering over the triangulation and selecting properties, by selecting Solid > Properties or Surface > Properties.

In the Triangulation Properties dialog box, tick the box “Drape a registered image on the surface” and click the ellipsis button  to browse for the *.RIMG file. Click OK.

Now you’re done! It may take a few times to perfect this function but GEMS does a great job at image draping.

For other GEMS Tips & Tricks, check out Displaying Search Ellipses as Solids or Create and Display Isoshells from GEMS Block Models.

Felix Walraven

Felix Walraven

Technical Senior Manager, Natural Resources Industry Solution at Dassault Systèmes
Felix is a qualified Geologist and GEOVIA GEMS Subject Matter Expert, with more than 28 years of experience in the mining industry. He has worked in a variety of environments from open pit to underground and across precious and base metals. Felix has worked throughout Sub-Saharan Africa and overseas, and is based in Johannesburg, South Africa.
Felix Walraven

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