Saving Human History From Stupidity (with Autodesk Memento and Digital Manufacturing)

ANTIQUE BUST

The Story:

When out for lunch together with my colleagues in the Thai restaurant accross the street, we stumbled upon this very old-looking bronze bust (above). We admired it for a while and began contemplating on a few things about it.

Namely, we precisely recalled events of all that historical hertiage destruction by Islamic fundamentalists in Irak and the middle-east at the time, and how it had everyone very much fired up around the table. Our response to this was to establish a positive stance on the unfolding events, with the help of combined modern technology.

We took it upon ourselves to create a positive outcome from the negative. First to show that where is there is will to destroy, there is simultaneous and equal will to rebuild, and in the hope that such a project could serve as a stark example of technological progress and as an optimistic reminder.

Tutorial by Eric Lemaresquier (le FabClub Paris)

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The Tools:

Making use of Autodesk's Memento (a free photogrametric software) enables us to digitally capture/scan objects with our own camera. A 3D model is built on the autodesk cloud server from our pictures, along with its high-resolution texture, and delivered back to our computers as obj. or many other 3D formats.

We made use of this software to restore the ancient bronze bust mentioned, and aiming to the closest of its former glory.

To do this, we’ve had to combine the use of a modelling software called Zbrush (Pixologic) to rework the damaged parts of the bust, such as filling in the piece with new volume, resculpt the details, and insert captured textures back onto the model.

We then printed it in various supports: PLA plastic with our Makerbot Z18, 3D paper printing with our Iris MCOR machine, and 3D CNCed stone with our industrial partner Maillard & Maillard.

This type of capturing tool permits production access to some very various and very creative projects on a broad scale.

Link to Sketchfab 3D of Restored Model:

https://sketchfab.com/models/71c02de07dfd47bd87299...

Link to Sketchfab 3D of Original Model:

https://sketchfab.com/models/d235a6e15fe54e3aada33...

Link to Maillard & Maillard industry :

http://maillard.normandy-craftsmen.com/maillard0.p...

To capture the object in Memento, we made sure of certain factors for optimal capture, mainly :

- Diffuse Lighting environment. Singular directional lighting was avoided.

- Homogenous colour in every picture, and No Blurry pictures.

- Diverse environment. Memento required as much details in the background as possible for optimal capture.

- At least Two full 360° turns for picture-taking, one at 90° from the front, and one slightly above at 120°(see diagram above). An optimal number for an accurate mesh creation is around 150 - 200 pictures.

- Overlapped pictures. We made sure to overlap one pic after the other so as to maintain optimal mesh and texture info for quality creation.

Pixologic's Zbrush and its powerful topology tool called Dynamesh, permitted us to insert a primitive sphere volume inside the empty head, shaping it roughly close to the interior surface and welding it to the entire head as one mesh, all at the press of a single button. From there, this got us a base for the next step.

Using Zbrush's masking and polygrouping tools, we retrieved the still surviving and better quality parts from the model and sticking them back on to patch up the holes. Quite a bit of resculpting was done after so as to blend the seams with the model and to recreate lost details on many parts of the head such as the ears and some parts of the coiffe.

Using Zbrush's Spotlight tool, we imported our high-quality pictures of the model and used Zbrush's RGB mode to repaint the photo directly on the model, therefore saving a lot of time than if we had to recreate a UV map for the model from scratch.

When an object is printed from an A4 block on our paper printing machine, we recover the entire block with the printed piece inside. We then simply unmold the piece out by hand from the block and by using tweezers for the more delicate parts such as nose tips and sharper angles. It can be quite a time-consuming process, but also a very satisfying (or hugely disappointing ! ) one when uncovering the piece.

The piece itself containing 1212 pages, we had to divide the model by 3 so as to not produce it all in one go. An entire block that thick would tend to curve during production, and so producing a failed print. When dealing with pieces this large, we divide the print process accordingly and stick the printed pieces together by hand.

Varnishing each piece afterwards blends and saturates the model's colours and renders an overall and homogenous quality. It is also very preferable when certain places of the model's surface appear too white or in too much contrast with the rest of the model. To do this we recommend to spread white paper glue or "deco patch" on the surface with a small paintbrush. You should also make sure to remove any excess glue so as to not end up with lumps on the surface.

Thank you.

Eric Lemaresquier, Fabmanager at the FabShop Paris.