The following post is by a friend of mine, Nate Hunt. Nate takes care of the family farm by day, and by night does CG renderings of North Korean missile launch sites. He often shares his work on facebook, where I’ve watched him hone his skills over the last few years.
A number of people have asked me to do short write-up describing a little about the current Tongchang-ri launch pad reconstruction work that I am working and why I am doing such a project along with the methods and tools I use for the reconstruction process.
To answer the first question, the launch pad reconstruction is actually a small part of a much larger project which scope is to accurately reconstruct not just the launch pad but the entirety of the North Korean West-Coast launch site that I am currently working on reconstructing in small stages with the launch pad being just a part.
The reconstruction is to provide a comprehensive reconstruction tool of said site for research and to help gauge changes to the site overtime which is useful if one has an accurate model to compare top down images with to better understand how things may be have been changed or removed over time.
Currently at this time the launch tower and pad area is at around 96% complete with minor changes left to be done on the tower and fuel buildings and fuel pipes.
The problem that arises when approaching such a large project is not just the large scope but also the lack of ground based imagery and with the Tongchang-ri launch site at the time no test videos had yet to be released showing the ground view of the launch pad area, this all changed on March 16th 2012 when the world community was faced with yet another in a long string of political escalations from North Korea when the country announced it was planning to conduct a new long range rocket/missile test of the countries Unha-3 space launcher that is based on the countries “Taepodong-2” long range ballistic missile which the country has been trying to perfect for a number of years now.
At the time while many in the press and world community thought the announced test would follow the regular path of previous tests, the North on the other hand took a surprise step when the country on March 17th just one day after announcing the coming test that the country was also inviting the world press and space experts to visit the newly finished Sohae space and launching test center on the West-coast.
As someone that has spent twelve years monitoring and studying the North’s launching sites from sat images released to the public and from press reports such as ones done about the test site on the east coast at Musudan-ri, I was very eager to see what photos and videos would be produced from such a onsite press visit that would help in my site reconstruction, for the first time it would provide the public with a grounds eye view of the launch site.
Tongchang-ri 3D Site Reconstruction Data Collection
Before proceeding with any site reconstruction it’s important to assemble as many reference photos of the subject being modeled beforehand, in doing this I regularly look to one of the following for sources.
- Google image search
- Image file hosting sites
- Public Community forums
In searching and doing such data collection it is important to not limit the search to just English spelling searches but also use other languages with tools such as “babelfish” or “bing” to translate “Tongchang-ri” into different languages and then “google image” for those results or conduct “Forum” searches for these spellings. Also do not assume that the pictures one is looking for would be spelled correctly and one should also look for common misspellings of site names or abbreviations.
When doing the data collection for the Tongchang-ri site these where a few of the terms I used.
- DPRK Tower
- NK Tower
- NK TPAD
When collecting images for reconstruction these should be divided into separate categories such as the following
- Detail image: Is any image that although may not provide a wider view of an area but is focused enough to provide enough detail to increase accuracy of a single point.
- Base Images: Any image that is not a high res zoomed image but provides a clear length and height of an object and will be used for creating the basic shape of a part that the “Detail Image” will help to fill in later.
Post Data Collection Processing
Once I have collected enough source images I will often find it needed to do some clean up or enhancement on images that may be too dark such as on the underside of the Tongchang-ri launch tower level’s ceilings to be able to count the floor supports. This can be achieved through running the source image through a photo editing program such as “Photoshop” or the free image editing program “Irfanview” and applying color and contrast corrections.
A good example of such a color correction enhancement is in the following images and shows before and after image of attempts to coax more detail out of three photos.
In the following image the inside of the Unha-3 first stage and section is darkened by tweaking the color, contrast and brightness settings on the image the underside can be made to be a little brighter thus bringing more details out.
Second Images shows an object streaking across the sky, applying a few color and depth filters help bring out a little more shape from object and devine the contrail better.
Third example of color and image enhacement shows ships in heavy fog, in the first image the shapes of the ships is obscured by distance fog but apply color and depth filters to the image brings out more detail along with the smaller boat in the fog.
Results will vary when doing color correction due to pixel resolution of the image in question so if one image may not yield results desired try them on other images of the same area and see if these fill in any more detail that may be missed in the lower res images.
As for what I use for doing my reconstruction work, the majority of my work is done using the Google sketchup program along with its image matching tool to construct the basic parts of the 3D model and ensure proper scaling before exporting to a secondary program for final adjustments. Once I have compiled enough “base images” I then load these in sketchup with the image matching tool to ensure proper scale and placement of parts. The following shots show how with proper alignment in the image matching tool very quick accurate reconstruction can quickly be achieved.
Post object creation rendering
Once I am finished with outlining the basic shapes and parts in sketchup I export the components out to the open source modeling program “Blender” for final clean up and adjustment for rendering!
One parts are finished being adjust I run them through the render to see how the mesh looks with shadowing and lighting
I have also been asked how I fill in areas that are not shown or are only half shown in images, I do this by a combination of photo combination and object placement matching estimation.
An example object placement matching: In December following the first successful launch of the countries Unha-3 rocket that followed the failed test launch that took place in April 2012, North Korea as part of the PR done for the successful launch released on national television the first public images showing the inside of the Tongchang-ri rocket/missile assembly building that the countries leader visited before the test launch.
While some images only showed the front left hand side of room or the very back left hand or right hand side of room there seemed to be none that showed the front right hand side of room by the front entry door. After carefully looking through the released images of the visit I noticed it showed a set of crates by the front entry blue door these same shown in another picture released from Kim Jung-Un’s visit to the site and match.. Thus I was able to estimate that if the crates are indeed the same then there is a corridor going to the rest of the building on the right hand side of door, with that estimation I updated my draft model with the changed estimations.
Many thanks to Nate for shedding some light onto an uncommon and fascinating hobby of his.