Week 7- Troubleshooting and Lighting Refinement

My first priority this week was to troubleshoot some of the render issues that came up in the latest batch of renders. One problem we were facing was that in Shot 01 and Shot 02, the motionvector aov was empty even though Motion Blur was turned on in Render Settings. I tried turning on Deformation and that seemed to give some information in the motionvector aov.



But it also caused the wheels to shrink in the beauty render.


I tried checking in the Maya scene to see if the rig was working and the scene was assembled correctly. Everything looked fine. So I decided to select all the controllers and bake the animation. And this seemed to fix the issue.






The other problem was in Shot 05, where the car disappeared from the render after a certain frame even though it was visible to the camera in Maya. I checked if there was enough light at the car position, if the car was going through an image plane or if the car was outside the skydome region. None of those seemed to be the case. So I switched to alpha mode in the renderview and scrubbed through the frames.


It looked like the car was getting clipped after travelling a certain distance. After I changed the Far Clip distance on the camera, the car showed up in the rest of the frame range.






Next, I wanted to address some lighting notes from the mentors for Shot 05. The car looked over-exposed(possibly due to the area light I was using as key light) and it also seemed to lack variety in reflections from the right. 

Color grade and comp by Camilo G.

I reduced the exposure on the key light and also adjusted its angle so there was more contrast on the car.

Before

After


To get better reflections, I created a plane and matched it to the position of the building behind the car. I then made a spherical projection of the hdri, with an aiFlat shader, on the plane. I adjusted the exposure on the file node for the hdri.





Before

After

 This is how the lighting slap looked.




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