Modelling and Rig

My intention for this model was not to come out with some crazy weird design and cool story to boot. What I want to create is a photo real as possible arm. I have been working a lot with Vray recently and it is fantastic as producing photo real renders, so this inspired me to create a photo real arm.

Here are the reference images I have been using to help me model the arm rig. The images of the hands are the ones Dev and Sanjay gave us, and the muscle image was to help me plan out the topology based off the twists of the muscles.


I started off by just blocking out the main shape of the hands, trying to the the proportions of each individual element. Once I was happy with the shape I began adding edge loops to start defining the main features.


Here I am still in the process of just getting  the shape of the main body, and defining the knuckles on one finger. Then I duplicated/scaled them into place. Using the merge tool and polygon append I was able to attach the fingers to the main body mesh. Now that the form has come together I can smooth the mesh and work on the details.


Now that the main shape the of hand is finished i can move onto the arm. I am using this muscle reference to help me match the topology to the muscle twists in the arm. This will help later when rigging the forearm twist. I have used a mixture of soft select and Maya sculpting tools to help morph the mesh into the correct shape.


Once I was happy with my model in Maya, I imported it into zBrush so I could add the xtra details into the fingers and knuckles, add some texture to the skin so it doesn’t look so smooth, and some veins as the model is quite muscular. With this high poly zbrush mesh i then baked it onto the lower res mesh in Maya because a mesh with 1.2mil polys would not be useable to animate on. The bake comes out as a normal map which I can apply to my Vray Sub Surface shader.


The rigging process I found quite easy. before this unit I already understood the basics of rigging from last terms unit when we created the swan rig. Something like an arm wasn’t too hard to make. Although one cool thing I picked up was with the forearm twist, using the expression  (forearm_L_joint.rotateX = wrist_L_ctrl.rotateZ *-0.5;) so that the forearm would twist at 50% of the wrist to avoid the abnormal twist that would occur only at the wrist without this expression. Once all the joints and their corresponding controllers where in place and working, I could work on the painted weights of each joint, this tends to be quite a time consuming process especially when it needs to be done for each finger and its joints.



Now that everything is in working order I could work on the rendering process. To get the proper skin like texture I am using the Vray fast SSS shader I have been using for the RSA entry. when combined with the normals map and a bit of texturing on the diffuse channel it produces some very realistic results. To create the UV map for the arm i have been using UV Layout , a program that Josh introduced to us, which is especially good at flatting complex meshes.


Here is a quick animation showing the movement of all the joints working together, and also a hi res render showing the final look of the arm.