Jack in the box







Project Overview

The jack in the box project is my introduction to Pixar's Renderman. The premise is to create a pop-up book in the real world and then develop a 3-D model to represent your real world creation in Maya through Renderman.

What follows is the journey so far when it comes to inspiration, previsualization and mock ups to the model itself and the progression towards completion.

This is Georges Melies ( 8 December 1861 – 21 January 1938) and one of my major inspirations for this piece. He was one of the first to enter into the world of special effects in films. In his own film "A Trip to the Moon" (1902) there is a very iconic moon with a face that has a bullet embedded into it. With this in mind I imaged a city popup world intertwined in the classic Melies world.




Georges Melies







The creation of the pop-up book required some elementary research. This was my first time creating an image with the intended effect of popping up and I found several tutorials online that assisted in accomplishing this task. The largest problem was stacking multiple layers of popup material to create an illusory foreground, midground and background.









Modeling a pop-up book and combining realism with impossible real world imagery has been a small struggle that I'm still tackling. This was the stage where it looks very much like the mock up created but I'm now realizing that I haven't put nearly enough of a twist on a pop-up book coming to life. Solving this problem while familiarizing myself with the tools Pixar's Renderman has available are my current goals.

This was rendered with Maya's software renderer before my introduction into renderman and also before the model's UV layout occured.



The image is pixelated because of rendering in a lower resolution but this was my first Renderman render with the new model (see problems section for details).



At this point I've begun painting the UV layout for the cityscape. The final UV's will be shown after the scene is fully textured.







The UV layouts for the cityscape were definitely the most time consuming but also the most enriching to the piece itself. The one mistake I will never make again was creating UV snapshots that were far too small for the amount of detail I wanted to display in the final render.





After laying UV's I began lighting the scene. There were some difficulties which will be later explained.



environment light only



environment light with mesh light



window/sign lights added/added stars/replaced backdrop with textured ground





image retouching in Nuke (denoise, color correction, reformating) located at the top



Challenges of the Project





The majority of the issues with this project consisted of familiarizing myself with Renderman and how different components within the plug-in integrate with Maya. Sadly my issues with Renderman began with merely installing the plug-in on my home station. The process seems very simple and trully it was the fact that I made it personally difficult more than anything else. When installing the plug-in you cannot install the installer in a separate folder from the location you wish you install the plug-in itself. I have multiple hard drives on my computer and have one folder exclusively for downloads and didn't not anticipate this being an issue. It was most certainly an issue and a simple yet unexpected one that took reinstalling Maya twice to figure out was indeed the source of the troubles. So, when installing Renderman make sure to install the plug-in where you want to install Renderman as this is where it will initially license your software before installation.

When it came to the workflow of creating the scene itself it was quite straight forward. I had the previsualization with the hand made pop-up book as a visual aid towards the final goal. It did not have to be photorealistic but I wanted to follow the guide created as close as possible to not deviate from the original idea. The imagined cityscape was the one thing most closely executed from the previs and that was to retain the kind of sketchy nature of the piece. This project did have time limitations per section and the tightest time crunch was certainly a tie between two sections, lighting and texturing. The modeling of the moon did take some time to get a close Melies moon using a reference from the movie noted earlier in the project overview, but that was nothing in comparison to figuring out how to light the scene in a very specific moon-centric fashion and texturing the cityscape to capture the moody atmosphere.

Doing the UV layouts for the majority of this piece was quite simple; snapshot the appropriate areas then bringing in the snapshot to Photoshop for laying down the appropriate textures. The difficulty, as previously stated, was creating a non photorealistic cityscape but still giving the feel of a city popping up and still easily readable by the viewer. The collage of reference images, overpainting and layering that ensued ended with a solid result.

After modeling and texturing, laying out the lights was tricky. Creating an environment light looked nice but it didn't give any character to the scene itself which was going to be directed heavily by the lighting. At first I thought PRM had an innate ability to make shader into a light source but after some research I found I was mistaken. With the help of the professor I was able to begin with a mesh light which takes the geometry of an object and uses it as basis for the emitting light. The major draw back to this was that the geometry used was effected by the new mesh light, thus completely blowing it out and basically turning it into a mini sun.



The resulting lay of the light is fantastic, but the destruction of the geometry was far less than ideal. I began looking for a solution that went from attempting to light link it out of that select geometry, which causes the light to turn off all together, to scouring the web for information on this particular topic with Renderman in mind. The problem was everything about using geometry as a light source was outside of Renderman and what little I could find about PRM light mesh led me into disconnecting/removing the bxdf, which is the pxrlightemission. I couldn't figure out how to disconnect the bxdf without the light ceasing in my scene. It was a frustrating ordeal and finally instead of complicating my understanding of Renderman further I decided experimenting with different techniques to get my desired result.

The final fix was using a glasspxrlm in the material attributes of the pxrlightemission with absorption at 0. To keep the original geometry uneffected by the mesh light I duplicated the geometry and used the duplicate as the meshlight. Once the geometry is duplicated with the light mesh applied and the glasspxrlm in the material attribute node of the pxrlightemission, you can then light link the entire scene minus the original geometry to the mesh light. This allowed the light to still be produced but also to keep the geometry from being altered by the light.





Now I merely created a base light to illumate the moon and bullet separate from the mesh light so that there is a soft glow coming from the moon itself.



The results were pleasing but space still felt quite empty. I added some elements to the scene with the stars and additionally created a light source for each individual red window as well as the signs to spice up and bring attention to the cityscape after the moon. The backdrop was also very plain which was fine for drawing attention to the focus of the book but it felt so plain that it was doing the exact opposite. A simple wood texture layed on top of a cube did the trick. With the light coming directly from the contents of the book, a reduction in the environment light to -3 allowed for an ambience of darkness with the book itself being the primary source of light and thus focus.