When I started working on the wheelchair I began with primitives and made sure the shapes worked well together. Once happy I proceeded by refining the shapes. Most of the chair is modeled in Maya, but I sculpted the leather seats, wooden ornaments, wear and fine detail in ZBrush, and retopologized it as I went along again (Fig.04).
I wanted the fabric, chair and basically the entire scene to look worn but not too old. Whilst I was playing around with the shaders I had an idea about which colors to use as a base. For the wood, iron and leather materials I used high resolution images that I projected onto the model in Mudbox.
When creating the shader for the clothes I used the Additive (shellac) mode of the VrayBlendMaterial (Fig.05). To blend these I created two VrayMtls, one for the pattern and the specularity and the other one for the velvet effect.
I used the fabric shader to procedurally tile the pattern. To do that, I created a seamless pattern in Photoshop. Then I adjusted the color and plugged the Out Color value to the shader's diffuse channel. I also included the reflections in this shader as well. For the reflections I created a samplerInfo node and plugged its facingRatio to the uCoord and vCoord of a ramp. Using the ramp's values I adjusted the reflection on the surface.
For the velvet shader I used pretty much the same trick, but this time I adjusted the diffuse aspect of the material instead of the reflection using a samplerInfo node and a ramp. For the Subsurface Scattering shader I once again used a VrayBlendMtl in Additive mode. The reason for this is because I could not achieve a decent specularity with VrayFastSSS, so I used a VrayMtl to get the effect instead. I created a VrayMtl for the specularity and a VrayFastSSS to get the color and scattering, and blended them in VrayBlend Mtl (Fig.06).
When I began lighting the scene the first thing I made sure to do was to set up V-Ray for linear workflow. After experimenting for a while I ended up using four V-Ray rectangular lights. V-Ray lights are pretty straightforward and work pretty well by default so I did not really tweak them that much. I mostly worked on the light color and intensity.
When I felt comfortable with everything I started working on the fuzz for the clothing and the legs. For this I created a separate scene with the same V-Ray and lighting setup. I then selected the surfaces I wanted to grow fuzz from and adjusted it using Shave and Haircut.
Once everything was rendered I combined it all in Photoshop. I adjusted the backdrop by adding a smooth purple gradient to compliment the green chair and emphasize the character a little more. I also added the smoke effect and hair in Photoshop courtesy of some high resolution images that I painted over to get the desired effect (Fig.07).