Strap On Matures

Given the absence of pre-Columbian agricultural tools at Pachacamac, I could not model an authentic coastal chaquitaclla. However, Dr. Erickson possesses a modern chaquitaclla which resembles those used by farmers living at the site in the past. I visited the Penn Museum to study and photograph the chaquitaclla to better inform my modeling process. There, I analyzed the object from multiple perspectives, taking note of how the object was constructed (Figure 8). I particularly focused on the complicated leather strapping which holds the chaquitaclla together (Figure 9). In addition, I observed the highly variable wood textures found throughout the chaquitaclla. The shaft and handle contained regions of polished wood produced by hands rubbing the surface over years of use (Figure 10). Aging had also darkened the wood and raised wood grains, resulting in a roughened appearance in other regions. I also observed several areas with relatively deep cracks. Throughout this process, I took dozens of photographs to use as reference while modeling the chaquitaclla. After this initial study, I began to produce my 3D model in Maya.

strap on matures

The basic structure of the chaquitaclla consists of the main shaft, the curved handle, the footrest made of wood, and the steel blade which are bound with leather straps. I imported reference photographs depicting the entire chaquitaclla and reference photos focusing on the individual components. I modeled each of the four components separately, beginning with the curved handle. First, I created a polygon-based cylinder in Maya. I then extruded the face of the cylinder with strategic rotations of the faces to produce a curved appearance. However, my initial attempt produced an unnatural and unrealistic curved handle (Figure 11). I had mistakenly selected the entire object before extruding, which disturbed the rest of my manipulations of the cylinder. I restarted with a new cylinder and extruded with soft select until I achieved a more natural looking handle (Figure 12). While possibly creating a similar or better effect with the Bezier Curve Tool, I chose to focus on producing the other parts of the tool before perfecting the handle with this approach.

After making the handle, I moved on to modeling the footrest. I first created a cube which I scaled to produce a rectangular prism. Then, I added edge loops and moved some vertices such that I could extrude parts of the footrest (Figure 13). This approach mimics the concave section in the footrest where the leather strap is located (Figure 14). Then I used soft select to extrude the lower part of the footrest to achieve the more detailed structures in this section (Figure 15). Although apparently simple, achieving the natural appearance of the footrest produced over years of use was difficult.

For my second approach, I first created a cube and extruded it with rotations to form a blocky, oblong torus shape. My first attempt produced an odd shape which would certainly not work for my straps (Figures 26). I started over and created a U-shape by extruding a cube with rotations (Figure 27). Then, I duplicated and rotated the shape to mirror my original shape. I then removed the faces of each shape and used the Target-Weld tool to join the two shapes together. This produced a more symmetrical shape that I could use to mimic straps more effectively. I used a similar approach of duplicating, translating, and rotating many of these fake straps along the chaquitaclla (Figure 28). I carefully achieved the crossed-over strap appearance near the footrest by rotating the straps (Figure 29). While I chose not to model the knot which secures the end of the long leather strap, this might be attempted using an approach employed by classmate Davies Lumumba. He produced a simulated rope appearance by twisting several polygons together, which might allow me to simulate a knotted appearance. I also found obtained a more natural appearance by soft selecting faces in the center of the strap and scaling them down. This replicated the appearance of tension which would have been produced when wrapping the straps around the tool.

Not only had I planned on modeling one team working on a field, I had also intended to depict multiple teams working on a field communally. To do this, I would vary my original chaquitaclla model using free-form deformation such that each team used a slightly different tool. Unfortunately, the method employed to simulate the straps would make this difficult and time-consuming to achieve. After manipulating any component of the chaquitaclla, I would have had to adjust all twenty solid polygons used to simulate straps. If known in advance, I might have learned the more time-intensive sculpting method instead.

Although adequate, the textures remain imperfect. After listening to other student presentations, I became aware of UV mapping approaches to texturing as well as a site where students obtained free textures. In the future, I would attempt to implement these approaches in my own model. After browsing the PBR website for wood textures, I failed to find a texture which improves upon the one I already selected. In addition, the site only provides leather textures for use on leather furniture which do not work for the leather straps. Given more time, I would learn how to create my own tileable textures using the textures from my model as references. 041b061a72