Building a Rig for Shadow Sculpture art in 3D

I researched and analysed methods for constructing the shadow sculpture of a human model in 3D Software and building a practical rig for the said sculpture that deforms the shadow realistically. For my Project, I downloaded common trashes, plastics and metal scrap meshes from online and used them to build the shadow sculpture in 3D. Then I tried to build a rig for the shadow sculpture. 

The project was heavily inspired by Tim Noble and Sue Websters Work. Their choice of objects for the sculpture is mostly metal scarps, plastic takeaway containers,  household trash items and other unconventional objects. Using these items, they usually build the silhouette of their body figure. I used the idea of Noble's and Webster's ideas of working with unconventional objects, for my work. 

Pre-Production

The initial task was to acquire the meshes for the sculpture. I downloaded meshes that are metal scarps, plastic bottles, plastic cups, soda cans and even some fruits and vegetables.

I scaled the meshes only once to bring all the items to a realistic size, after that I locked the scale option and never used it throughout the project again. This is so that I can stay true to the real-life art form of shadow sculpture.

The next step is to build the human rig. I again downloaded a Human Mesh online and built a fully functioning rig with an IK/FK setup for the Human Mesh so that I can compare the deformation of the body and the shadow. I will be using the same human mesh rig for shadow sculpture, to test how the sculpture adapts to a simple Biped rig.

After completing the rig, I built a simple lighting setup for the shadow and locked camera view.  

After acquiring sufficient meshes and completing the Human mesh rig,  I started building the shadow sculpture. Here I experimented with two different approaches to shadow sculpting.

Method 1 

In this method, I started to arrange the shadow sculpture meshes(Trash object meshes) to fit inside the Human mesh and follow along the shape of the mesh. This means I didn’t have to work with the light render or the shadow reference of the Human mesh. Instead of working with the locked camera, I worked on the front and side view so that the meshes properly sit inside the human mesh.

After fitting all the possible meshes into the human mesh, I connected the human mesh rig to the sculpture. I found that skinning the meshes to the joint chain would cause unrealistic deformation of the meshes( metal scarps bending wouldn't be realistic) Instead, I constrained the meshes to the corresponding joint. 

This method is relatively simple. It was just a matter of finding the appropriate mesh for creating the shadow of a body part. While I was able to finish this shadow sculpture sooner than I expected, this method doesn't hold up with the authenticity of shadow sculpture art.  

The main issue was that the collage of shadow sculpture meshes was giving away their shape. The true essence of the shadow sculpture art form is that we won't be able to figure out what shape the collage will represent nor estimate the shadow that the collage will cast. In my shadow sculpture, it was visible that the collage represented a Human body shape.

This method limits the creative freedom of using the lights to manipulate the shadow. Objects near the light source give sharp and small shadows and objects far away give a faded and enlarged shadow. I was unable to use this technique in this method. This limitation caused the inconsistency in the shadow deformation. The reason was that some shadow sculpture meshes I downloaded were not conforming or fitting inside the human mesh. Even though the human mesh rig worked effectively with this sculpture, the inconsistency of the shadow appears when a body part control moves. 

Method 2

I worked with the light source and the locked camera in this method. I arranged the meshes in random order, making sure that the shadow of the meshes aligned with the human shadow using the reference side by side. I worked in a layer-by-layer method. The collage was also an unrecognisable improvement from the last method. I also built another sculpture facing the side view. The sculpture also had less inconsistency in the shadow than the previous method, as I was able to use the light manipulation technique in this method.

After working with the front view, I started to work on a side view. I wanted to experiment with producing a full-rounded shadow sculpture rig, with all main orthographic sides rigged. 

The first issue was the shadow from the front shadow interfered with the side shadows, thus disrupting both silhouettes. There was no other way to go around without messing with either one of the shadow sculptures. Hence, I created a set-driven key that hides the front shadow sculpture when it starts to rotate. The ideal way of creating this 3d shadow sculpture was to work with both sides simultaneously, but it just added to the clumsy arrangement with neither of the views recognizable.

Building the Rig

The human Mesh rig didnt work at all with the 2nd Method of Shadow Sculpture. I had to build a new rig that accommodate the shadow sculpture.

I noticed in the human mesh rig that in the front shadow, IK functionality would not be visible. The side rotations are the one that makes sense when the shadow is concerned. Hence I focused on only building the FK functionality for the front shadow sculpture.

Since the meshes were scattered, the rotation will work properly with a correct pivot point. This part is entirely a trial and error process. I used locators to help me to test out different pivots. It has to be noted that some rotations, regardless of the pivot point, will not rotate properly. This will be counter-productive, as you would be fixing every single rotation value.

After finding the current pivot points, I replaced the locators with joints and constrained them to controllers.

I started to work on the side sculpture rig. In the side view, the ik legs, are visible. Unfortunately, IK functionality doesn't work on the sculpture. The scattered meshes were not coordinated with the IK handle. even locators weren't helpful at this point. hence I cannot add IK functionality to either of the rigs. 

Final Artefact

Critical Analyses

There were a few bumps down the process. The rig is not fully completed. I would look more into programming and scripting to speed up the process. The overall rig still lacks complexity and completion without IK controls. The rig could improve if all main sides were sculpted and rigged. It will give more controls for the animators to work on and will be fitting the name of the 3D Shadow rig.

Acknowledgements

I would like to thank Valery Adzhiev for Supervising the project