Annika Hottgenroth - Lighting Lookdev

I started the project as an assignment for our compositing course at PIXL VISN media arts academy, with the Idea in mind to gain knowledge on how to integrate a CG object seamlessly into a real environment.

I wanted to achieve an aesthetically pleasing project, as well as give myself a little challenge with having a lot of reflective objects and candles. 

CG Integration – sweet tea 

In the next slides I´d like to dive deeper into the process of creating my CG Integration.  

Getting started – filming and concepting

After I planned out my concept and got the assets, I arranged everything in a way that would be pleasing for the eye and then made the final decision on which objects I wanted to integrate. Originally, I wanted to integrate the spoon instead of the cup. After seeing it all set up, I thought it would be more interesting to texture and shade the cup with tea in it as well as it being more challenging in compositing to get all the reflections in the tea and porcelain just right. As I wanted to have a little challenge to recreate the reflections of the candles, I placed some smaller candles throughout my arrangement instead of just placing them in the background. I set up a rim light from the back left and a big softbox from the right to get it evenly lit. As the candles added warmth, I decided to also give the rim light a warmer tone, but generally tried to get a pretty neutral light so I could adjust it with grading in nuke afterwards. 

For the camera movement I decided to go for a simple pan from left to right, that would make the tracking easier, as it was the first time for me to track something with a 3D tracker setup.

After I filmed the clean plate, a reference with all the objects that were to be integrated, a plate with tracking markers to make tracking easier, I created a HDRI with the help of a 360-degree camera. What I didn't think of at that time was that I would need all objects, except the ones to integrate, in the HDRI as well so that I get correct reflections. Therefore, I had to recreate the reflections of the integrated objects per hand afterwards.

An important part was to take as many pictures as possible, from different perspectives, to get a good understanding of every light source. To match it in 3D as close as possible, but also for compositing, getting all the details just right.  

Diving into 3D – Lighting and Shading in Maya

After deciding to integrate the cup and the cookie I wanted to add one more integrated object. I needed something subtle and therefore decided to integrate a second blueberry on the small cake. The blueberry is shaded completely procedural in Autodesk Maya, only some maps, for example AO and Curvature, were baked in Adobe Substance 3D Painter, to make the shading tree less heavy. I wanted to use this opportunity to get better in this matter, as I never did it before. I textured the cup completely in Substance 3D Painter and made standard shading adjustments in Maya.  

The rendering was done in Maya with Arnold. To have more control in compositing, which was done in Nuke, I created sperate lightgroups. For ultimate control over every light, I separated the different lights into diffuse, specular, SSS and transmission channels, as well as rendering out all of the albedo channels of the listed above. That would give me the chance to divide the lightgroups in Nuke through the related albedo channels to get the light separated from the albedo, to only affect the light and not changing the albedo color, while adjusting it.

Rendering every object on a separate render layer gave me the opportunity to adjust them even more individually, especially fixing some minor sliding, when the track wasn´t 100% accurate. In addition to that I put the shadowmattes on its own renderlayer. I also separated the shadowmattes with help of a custom AOV per light, so I had the shadows cast from the different lights individually.

To add missing reflections, where the HDRI wasn´t accurate enough, I added cards with a light texture to get reflections in my tea from the softbox, aswell as two cards to get the reflection of the candle on the cup.  

Compositing - Bringing everything together in Nuke

Jumping into Nuke was mainly about bringing everything together. I started reconstructing my beauty and adjusting the blacklevels. I found it helpful to have a lightslap, allowing me compare my current comp output to it, so that I won´t go overboard. Having all my lights split up helped me to get all integrated objects to match as close as possible to my reference. For example, I had a highlight on my blueberry from my rim light that was just too bright if you compared it to the other blueberry right beside it. But having my lights split up in that way prevented me from having to re-render it again. This was especially useful for the shadows from my tea cup since some shadows were darker than others, so I could grade them individually. The ambient occlusion where the cup stands on the plate was barely visible, but the custom AO AOV didn´t help in that case. Therefore I used rotos to manually adjust them and tracked them to the cup. After studying the original plate for lens effects, I added defocus, chromatic aberration, halation and camera distortion. Before merging it to my backplate I also added some defusion with a blur, to match it even more. After that I de-grained my plate to use this to re-grain everything together at the end. Lastly, I added some color grading with help of LUT´s and manual grading as well as some bloom and a vignette. 

Conclusion

The biggest challenge in this project was doing everything from start to end. Not only the filming but also the part in Maya as I only did similar compositing before. As there´s a lack of an in-depth explanation of the proper workflow at the internet, it was a lot of research work, as well as try and error and asking other students and teachers for help. I´d like to thank Luise Rolle in that matter, for finding solutions with me. Emilio Lingg with compositing help. Leo Matull for modeling the cup and the blueberry and Fabrizio Meli as well as Marcel Pichert for feedback on this project.

In the end, I think there´s still a lot to improve and making the workflow a lot faster, but it was a great learning opportunity.   

Softwares used

Autodesk Maya, Arnold for Maya, The Foundrys Nuke, Affinity Photo and Adobe´s Substance 3D Painter. 

Credits

Cookie Model and Textures – Quixel Bridge

Cup and Blueberry Model – Leo Matull

Everything else – Annika Hottgenroth