Photography, 3D modelling and printing

head: Katarzyna Janiszewska
e-mail: k.janiszewska@twarda.pan.pl

Imaging Facility Form (link)
Laboratory Regulations (link)

The laboratory is equipped with a computer cluster, photographic equipment, 3D printers and software for digital photo processing and creating 3D models.

Creating three-dimensional models of fossils using the photogrammetry method: Agisoft Metashape software

Based on hundreds of high-resolution photographs of an object placed on a rotary table, the program creates a point cloud, a polygon mesh and then covers the digital model with a texture. Models made in this way can be used for morphometric analyses. Our Imaging Facility creates 3D models of specimens stored in the Institute's collection. Additionally, the program allows the creation of a model based on photographs of specimens taken in other scientific units or placed in publicly available electronic databases. Thus, the Institute's employees can work on virtual copies of specimens that are sometimes located thousands of kilometres away or are not available for research. When the planned analysis is destructive in nature (thin sectioning or isotope analyses), a virtual copy of the not yet destroyed specimen can be created. What is more, based on the virtual model, its copies can be 3D printed – an enlarged model, mirror-rotated or supplemented with elements known from other specimens of the same individual. This allows, for example, to create copies of specimens from a comparative collection of reptile bones, the holotypes, which are scattered all over the world.
The Agisoft software also allows the creation of terrain maps based on data from unmanned aerial vehicles (drones) – which can be used to develop maps of outcrops, landslide monitoring, etc.
In the Agisoft software models of specimens can be created based on a photograph taken with a camera, laser scanner, smartphone or a camera placed on an aircraft. Our laboratory is equipped with a basic set for photography (SLR camera with interchangeable lenses, tripod, rotary table, shadowless tent, set of lamps).

Helicon Focus and Helicon Remote software.
The Helicon Focus software automatically takes several shots at different focus distances instead of just one, and quickly combines the stack into a fully focused image.
The software can be used, i.a. for macro photography and to improve the quality of photographs taken under a microscope. The ability to adjust parameters and select image elements that we want to include allows for the creation of exceptionally detailed photographs. The Helicon Remote software integrated with Helicon Focus allows you to control a digital camera connected to a computer - automatically taking the appropriate number of photos with different depth of focus and managing the photography process (adjusting parameters) from a PC.

The laboratory is equipped with two 3D printers:
The Prusa i3 MK3S printer uses the FDM (Fused Deposition Modeling) method by printing  from a thermoplastic material in the form of a thick line - filament. The Prusa printer can use filaments with different physical properties, melting temperature, colors, and even glitter additives. The software divides the three-dimensional virtual model of the object into thin layers (from 0.05 mm to 0.3 mm). During printing, the device's head applies melted filament to the work platform according to the "outline" of the printed object. After printing the first layer, the head lifts slightly and glues another layer of melted (sticky) filament to the first layer, again according to a previously programmed pattern. The thickness of the printed layers can be changed - depending on the degree of accuracy of the model we want to obtain or the time we want to spend on printing. An object with simple shapes, e.g. a box for microscope stages, can be printed relatively quickly and from thick layers - about 2 hours.
However, if we want to print a fossil model and best reproduce, for example, the sculpture of the specimen, the thinnest layers are used, which significantly extends the printing time (even up to several hours), but improves its quality.
The size of the specimen that can be printed is limited to 21 x 21 x 25 cm, but the software allows you to divide the largest models, print them in parts and then combine them.
Due to the relatively low cost of printing and still good quality of reproduction, we use the Prusa printer for most specimen printing, including comparative models in the scientific projects of our employees. In addition, users create prints useful in the work of laboratories and the institute's collection - sample holders dedicated to specific specimens, additional elements for apparatus, containers for thin sections, various housings printed according to the individual needs of users, etc. Prints from the Prusa device are also used for lessons with students and popular science workshops for the youngest enthusiasts of paleontology.

Formlabs 3 printer uses the SLA (stereolithography) method, i.e. selective light curing of layered resin (differently than in the Prusa printer). In the software, the virtual model of the specimen is appropriately oriented and divided into layers. The layers are 25 micrometers thick. A thin layer of photosensitive resin is poured onto the bottom of the printer, in which the laser hardens only specific fragments, reproducing the shape of the model. The cured first layer of the model lifts, and the laser beam hardens the next layer. When the last hardened part emerges from the liquid resin, printing is complete. The maximum size of the printed object is 14x14x18 mm.
Post-Processing:
First, the model is placed in an ultrasonic cleaner, where the remains of unhardened resin are removed in isopropyl alcohol. The alcohol dissolves the sticky residues of the resin, but does not affect the fragments previously hardened by the laser.
Then, the rinsed model is placed in the curing (hardening) station - at a temperature of approx. 60-80 degrees, the model is exposed to UV radiation, which makes it hard and resistant to deformation. Finally, after removing the supports, the model is ready for presentation.

The precision of the Formlabs printer and the SLA method far exceeds filament printing. This device is designed to print models with a complex structure, porous objects, or specimens in which precise reproduction of all possible details is particularly important - e.g. when creating copies of holotypes of specimens collected in the Institute's collection.
The Formlabs 3 printer can print from various types of materials - resins can have different physical properties, you can print from "rigid" or flexible resins, freely choose colors and, unlike in the case of filament printing, it is possible to print transparent elements. The cost of printing is much higher than in the case of a printer using the FDM method, but the price of the equipment, accessories and resin is reflected in the very high precision of the SLA method.

Both printers mainly support the .stl and .obj extensions, but files/models in other formats can also be adapted for printing.