In 1998 I was working as a summer student for a coal mine in British Columbia, Canada. In the environmental department, I saw the process that the mine had to go through to get permits to expand or create new waste spoils. This mine was situated within city limits, and was poised right above a major highway, so the visual impact of a new waste dump would have to be demonstrted to the government before the permits could be issued.
The mine contracted with an engineering firm to create a mockup of the proposed new dump. This firm took a flyover photo of the mine, and "draped" it over a wireframe of a combination of the surrounding land and the proposed new dump. They then edited the flyover photo so that the new dump looked somewhat realistic.
However, the "photograph" that this generated had some shortcomings. Mines very often have steep walls, and when you drape a 2D image on to a steep 3D wireframe, the photo stretches out and looks unrealistic. In addition, the company decided to generate a black-and-white image, either because the flyover photo was in black and white, or because it possibly mitigated the effects of the vertical smearing seen on these steep vertical walls. Lastly, that one "photo" cost $50,000.
I decided that I could do better.
I asked for permission to spend some time to try to reproduce the photo myself, and I think I wound up with a better representation of the dump, at a fraction of the cost.
The procedure for this task is quite straightforward, but can be finicky to get realistic results.
This image took me a total of about 10 hours to create. I was using 1995-level technology, so
producing an equivalent image today would take less time and would look more realistic.
- A digital photo is taken of the site, and precise coordinates of the location of the photo are recorded
(using GPS, for example). Care should be taken to identify landmarks on the photo (power poles, bridges,
road intersections, creek junctions, etc.). The photo shown below had been taken the year before from a helicopter; I took some photos from ground level, but this one wound up looking the best. This photo was not taken with the intent to be used for this, we just found it after the fact and put it to work here.
This photo was taken from
a helicopter, which makes the task much harder.
- A 3D model of the area is loaded into a rendering software package such as Caligari's TrueSpace or Discreet's 3DSMax.
A camera is placed at the same location and orientation as where the digital photo was taken.
- The digital photo is made the backdrop of the render process. By manipulating the orientation and zoom level of the
camera in the rendering software, the landmarks in the model are lined up with the landmarks on the digital photo. By
doing this, the software camera is oriented in space exactly the same as the original camera.
- The 3D data is removed from the software program, to be replaced with the model of the proposed mining action. In this case,
a wireframe model of the proposed dump was imported to the rendering software from AutoCAD in DXF format. An image or
colour mottling is applied to the model, and then rendered against the digital photo backdrop. Lights may be added
to the render package to simulate the sun's shadowing.
- The rendered image may then be touched up in an application such as Adobe Photoshop, or the Gimp. This will soften the abrupt
edges that are prone to occur with the coarse engineering models typically availble in the planning stage. The rendering process
is typically quite iterative to come up with a realistic image; the amount of effort put into this stage is dependant on what
the image will be used for; i.e. if it is being released to the public, a great amount of effort may be expended in this stage.
If an image is intended to be released to the public, then care should be taken to take the original picture
from a position that is familiar to the public, for example from a well-known highway junction or with the
entrance to the mine in the foreground. That is, if more care is taken in considering the composition of the
photo, then a more effective image will result.
This is a great example of how having a technology generalist, in this case a mining engineer who has played with AutoCAD, 3D rendering software and PhotoShop can visualize an out-of-the box solution to a real-world problem, for a fraction of the cost and time.