Preparing a new wall texture for the mansio of Khirbet es-Samra

Taking a break from Qumran

I went back to the model of the mansio of Khirbet es-Samra for which Jean-Baptiste Humbert, archeologist, asked me to make a model. The current model, well under way, uses a wall texture of which none of us are really satisfied. The obvious problem is that the structures on site do not have any significant wall left. It’s mostly razed to the fondations and therefore do not provide any significant way of evaluating the kind of wall that once stood there. But a good starting point is to look at the much more substantial remains at the nearby Khirbet es-Samra, which are believed to incorporate the raw materials removed from the mansio.

One stone at a time

Based on the pictures of the Khribet, I started to model and sculpt some stones with the same technique I used for the stone wall texture of Qumran. It is a very time consuming process but to speed up the work, I decided not to only sculpt the front and side faces, leaving the back side untouched, but rather to sculpt the stones entirely. Thus, each stone can then be rotated on its six faces to create six variantes, and since I do not have to conform strictly to any given pattern, I can then use all these variantes to rebuild a similar wall structure as seen on the reference pictures.



Building the wall

After having sculpted about fifteen stones of varying shape and size in conformity, more or less, to the reference pictures, it was time to duplicate each one five times and rotate them so that each duplicate shows a different face to the camera. I then had 90 stones ready to be placed.

Then started the process of building the wall from the ground up, literally. As I was aiming at reproducing the natural placement of the stones in the wall, I started from the bottom aligning a row, then moved to the row above it and so on, trying to fill the gaps with smaller stones as a builder might do in real life. I must admit that my experience at building stone walls is minimal but nevertheless, my little real life experiment on the mountains of Switzerland wasn’t in vain, at least I like to think of it that way.

02Working with an eye on the reference pictures, I kept on constructing the wall but I choose to add slightly more randomness to the rows because of the only tiny bit of wall remaining on the mansio site where it seemed to be the case.

With the help of a simple plane, I levelled the front faces of the stones to give the structure an even aspect.

04As I was missing a few stones to complete the wall, I went back to the sculpting process and a few stones later, here I was with my finished wall. Of course it is build to tile seamlessly. The back of the wall is completely unequal but who cares.

03At this point, every stone was a separate object. This allowed me to place and make adjustments to the stones very quickly. However, because these were sculpts, the vertex count was quickly becoming very high. One way to avoid total meltdown of the computer is to keep the Multires modifiers and set the preview level to half or lower the resolution of the sculpt.

I already had a background plane for the seams between the stones, so I imported it and adjusted it to the proper size. Beware that this background has to be seamless too as some parts of its joining borders may be visible on the final texture.

05A limitation of Blender (the 3d software I use) is that it handles very poorly great number of separate object during the baking process. I found that I needed to join all the stones into one big object for any bake to complete successfully.

At this point, having applied all the multires modifiers with their maximum level of details, the polycount was just staggering, well at least for a 3 by 3 meters wall, reaching past the 19 millions vertices. Everything was slowing down as the computer struggled keeping track of all those vertices. Time to remove some dead weight. I deleted all the vertices behind the background plane and came back just under 7 millions vertices.

06Its was then time to bake the normal pass followed by the ambiant occlusion pass. Too bad Cycles doesn’t yet support the height map pass, and I am too lazy to go back to Blender internal engine for that. It’s ok, I can load the normals into CrazyBump to get a decent height map.

07Having done all my bakes, it was time for a little material node cooking to test my new wall on a regular cube, here with some subdivisions and a displacement modifier and at the bottom left: the reference picture taken at Khirbet es-Samra.

The albedo (color map) was made with a freshly shot set of pictures of some similar basalt stones from a different archeological site. The color variations were all done with material nodes.

What I have learned

If you don’t need to conform to a very specific stone profile, it’s quicker to model a complete stone and then use all of its six faces rather than sculpt five faces (front and sides) and not be able to use it for more than its front face.

If you make duplicates of a single object to use different portion of it (like the six faces of the stone), don’t wait until you have completed the whole project to decide to trim what you don’t need (like the back part of each duplicate). Make duplicates, rotate them as you need and then go ahead and remove the parts you won’t need before moving on to duplicating the next sculpt or model. Thus, you will always avoid reaching ridicule amount of vertices and your computer will always be more responsive.

It’s best not to sculpt the fine details like any stone decal brush or the like, because once sculpted in, you can hardly remove it and thus the sculpt is sealed. On the contrary, if you only sculpt the overall shape of the stone omitting the very fine details, you can always reuse the sculpt for different type of stone applying different finer details with decals or manually right before the bake. Thus creating different models with the same base stone, saving a lot of hard work and time.


Qumran IIIA is on its way.

530 pages later…

After more than a year of hard work with Jean-Baptiste Humbert, we finally completed the publication that was in the making long before I joined the project. The complete book as been delivered to the publisher in Germany and is on its way first to the printer then to the bookshelves.

Qumran Volume III A Book Cover

It has taken a considerable amount of work to make it happen. Days and nights spent assembling all the material meticulously and in the end always the haunting of possible mistakes that crept in unnoticed. I can’t wait to see how it will be received by the Qumran specialists community.

Just a brick in the wall…

Testing some brick texture for the Qumran model.

Bricks in Qumran? Yes of course there are those buildings on the South-East whose brick-walls are still apparent to this day. But not just those. In fact many of the buildings, including most of the pools or reservoirs had almost certainly mud-brick super-structure. This is why many stone walls are so uniformly levelled, they were the foundation upon which the upper most structures made of plastered mud-bricks–that didn’t survived time and weathering–stood. Well, at least not in their initial form since in fact their debris filled the site to the point where it was barely visible when archeological digging started in the 50’s, apart from the famous so called tower whose top was above the ground.

So, following the same method used for the stone walls, I started creating some brick shape only this time it wasn’t necessary to use photo reference to model the shape since a brick  is, well, a brick. Only the scale mattered in this case.

Qumran Bricks Sculpt Test 1

Once the tillable brick wall was sculpted, baking the normal map, AO and height map was done. Then, with help of photoshop, I made a cavity map that will help later on give some extra definition to the color map in the shader.

This is the result on a cube with a simple shader using normals, specular and height map for mesh displacement on a subdivision modifier.

The corners are not addressed here as the bricks simply continues from one side to the other without angle consideration which should ultimately show the actual width of the brick and not the next brick. Something I need to consider.

Qumran Bricks Sculpt Test 2

On a continuous plane, the texture is perfectly tillable. With the help of an extra layer of noise displacement on top of the actual brick displacement, it becomes even closer to the originals. I may have to adjust the scaling of the texture to better fit the reference material.

Qumran Bricks Sculpt Test 3

Next thing, I will have to dig in my Qumran photo library to find color reference and adjust the texture color to match real bricks. However this is rather not so critical since almost all the time, it will be shown covered with plaster.

Qumran Archeology

Building a 3d model of Khirbet Qumran.

I am not the first nor will I be the last to attempt a 3d reconstruction of Khirbet Qumran. However,  all that has been made available to this day on the subject is somewhat incomplete and either partly inaccurate, fantasy or subject to strong questioning. Therefore, working with archeologists to reconstruct what the site of Qumran might have looked like was a challenge that I could not pass by.

The first thing was to build the main structures of the wall and loci. That was the easy part since it is basically just redrawing the map of the site and extruding to provide elevation. That is where problems arise. First, we don’t know how tall the walls were, nor do we know with certainty how many levels there were in the buildings. Then, an other problem comes along which I believe has largely been either ignored or underestimated: the ground is uneven and there is a slope going from West to Est on the site, which means not all ground-level buildings are at the same elevation. This is evident to any observer on the site, but on the computer or on paper, it is often not shown or discernible. This might seem trivial but it is extremely important to the volume reconstruction of the site as adjacent structures do not necessarily nicely align horizontally as often imagined from looking at the plans. The whole reconstructed aspect of the Khirbet must therefore take this into consideration.

Texturing the model.

Early on, I was asked to provide some illustrations from the work in progress and was confronted with the difficulty of texturing the model. Relying on generic rock or stone textures definitely was not a nice option. What else? Paint the photos of the real stonewalls themselves on the model? Very hard to do if possible at all given the number of pictures it would require, not mentioning that most walls are now long gone. I choose to try something in the middle: create a generic texture but from the real material. So I went back down there (some 450 metres below sea level, and no I didn’t have to dive) and started shooting some reference pictures.

Back at home, using the photos as guide, I started the tedious process of recreating the stonework in Blender to build a 3d model of a portion of the wall.

Screen Shot 1

Once the stone themselves where built, I removed the seams and a duplication of the whole area made the process of checking the tiling of the pattern easier.

Screen Shot 2

Then, extruding, subdividing and sculpting took place. Very lengthily process as I had to sculpt every stone individually but in the end the result is quite acceptable I think. It could still be improved, but as a first shot, that’ll do for now.

Screen Shot 3

After this, it is just a matter of baking the normals, height map and ambient occlusion to give me a good starting point for building a tillable Qumran wall texture.

Now this is what it looks like with some experimental shader on a mesh with a displacement modifier.

texture wall 8

texture wall 7

Of course, it would be difficult and prohibitively resource intensive to apply mesh displacement on the entire model and this method is exclusively reserved for closeups shots. For far away shots, normal map will usually admirably fit the bill. This is what it looks like (with a slightly different shader) on an early and incomplete model of the Khirbet. It does not yet incorporate the terrain of the site itself but I’m working on it.

Model Preview 36

The work got started some months ago but was interrupted by other works underway that engulfed all my available time. As this diversion is coming to an end, I will resume my work on 3d Qumran momentarily.

Will we manage to produce a viable proposition of a reconstruction of the site? Time will tell.

Working with archeologists…

Through an acquaintance, I’ve had the chance to meet archeologist Jean-Baptiste Humbert about two years ago. We quickly developed a friendly relationship and one thing leading to an other, I’ve been working with him for the last two years doing various 3D illustration projects and other graphic works.

When I was asked to give him a hand to finish one of his most important project, namely the publication of the third volume of the excavations of Khirbet Qumran, I jumped in not really knowing how much work and effort it would require from me. That was several months ago, and at that times, it seemed like the project was almost completed as Jean-Baptiste and a few other people had been working on this project for many years already. Since then, I’ve been working like a horse to pull all the remaining tasks to completion and it’s been quite a ride, and a tremendous amount of work. Spending days and nights, at times sitting side by side with Jean-Baptiste, in front of a row of computer screens, checking layout, hundreds of rows of reference numbers, drawings, photos, adding, removing, correcting, creating…

Then going back home, continuing the work well past midnight and going back again, a few days later, to meet with Jean-Baptiste and review together the corrections. Sending the text for proofing, getting it back, making some changes again, sending it again. It’s been months of work now and while there seem to be no end to this process of corrections and improvements, we are finally reaching the end of it.

From what I understood, there is a great deal of interest in the archaeological community regarding this publication, and probably some weariness regarding its constant delaying. We work hard to bring this work to completion and I dare hope my intervention in this process will be beneficial both to the reader by providing a volume that is pleasant to read and consult, and to Jean-Baptiste by helping him producing a book that will translate his work as best as possible.

In the meantime, I get back to work.