Understanding Circular Polarizing Lens filters: Light reflected by water surface is horizontally polarized (water itself acts like opposite of polarize filter - instead of letting only one polarization through, it bounces it off). Using a vertical polarization filter filters out the horizontal polarized light reflection therefore you can finally see underwater in photo.
Amazing homie! I've always wanted to learn how to do this since starting my VFX journey a few years ago! A few things I'd add tho is suspension physics on the car, (subtle), surface imperfections, specular in-camera effects in regards to the metallic car materials according to the angle of the sun, slight motion blur (very subtle), and i think last but not least exhaust fumes from the car (its probably subtle for this kinda car, idk lmao im not a car guy) but nontheless amazing my guy i still needa learn how to master this process but as time goes by I'll try to improve my renders to include all of the above! Cheers dude, keep doing what ur doing!
Hey - Thanks for this. I've heard tell of photogrammetry software struggling to detect spatial positioning with stationary camera, as in your setup - have you run into this problem? I'm going to be using Reality Capture
Hi great tutorial! i have a question, the cross polarization only works with a single light source? what happen if i use two lights with polarization films at the same time? Cheers!
If all your light is polarized the same direction, then it should work with multiple light sources, but it becomes increasingly difficult to control with more light sources.
Yep I can confirm what Zuriki mentioned, I tried cross polarization with two studio lights today. The two lights are angled 45 degrees from the camera, positioned on the left and right side of the camera. I used a linear polarized filter and taped it to my light. I made one mistake, I didn't pay attention to the rotation of the polarized filter on the second light. The filter on the second light blocked majority of the reflections but on heavy reflective/specular materials the reflection was still noticeable. I removed the linear polarization filter and rotated it 45 degrees in front of the light, while looking through the camera to check if rotating it would affect it and it did. To make it work you need to tweak the polarized filter on the second light just as you would tweak the CPL on your camera. This means that to create a clean setup I would need to build a filter that I can rotate for my secondary light source. In case my lights move around, I will need to have the control to tweak the angle of the filter. EDIT: Just slapping 2 Linear Polarized Filters on your lights is still better than nothing. My setup without tweaking the polarized filter on the second light still eliminates all the reflective/specular details. Things like shiny plastic works perfect. It is as soon as you try to remove reflectiveness from metal subjects that you will need to tweak the polarized filter on your second light.
that was a good intro for the workflow... however theory from practice is something very very different. Looks easy but it isn't at all for us who we are beginners. We would appreciate a tutorial :)
For CG objects that will be partially obscured by the original footage, will you have to mask it out frame by frame in compositing or is it possible to set up certain "objects" in blender that will not render the main CG object when it passes through that "object"?
The shadows are done perfectly.. but the spinning animation of the wheels seems weird.. guess the model is supposed to be used for a car driving at higher speed..
