This blog will document the process of Project 1: Lighting CG Objects through Compositing for Professor Gaynor's TECH420: Technical Compositing Class at SCAD Savannah based on in-class lectures and demonstrations.
1/8/2022: The first step of this project is to decide whether I will be taking my own photos or using an existing photoset. I wanted to take my own photos, but was not able to obtain the needed equipment in time. I am excited to take my own photos for Projects 2 & 3!
For this piece I will be using a photo set from the class library courtesy of Sarah Van Alstyne. Thank you Sarah!
To begin the process, I brought the cube photo into Maya and set up the camera to match up the perspective.
By using the metadata from the photos I was able to see the resolution, focal length, and camera information, which I then used in Maya to accurately create the camera.
1/10/2022: I am also still brainstorming what objects I would like to roll through the shot. My current ideas are lemons or a gold vase.
References from Unsplash.
1/11/2022: I continued working on the project by adding in a keylight and matching up the shadow from the plate to the shadow on the CG plane. I also added fill light using the chrome ball image from Sarah's photoset. I generally use a geodome for positioning the lights, and a skydome for rendering.
Once I was happy with the cube match, I moved onto matching up the ball and working on the light intensity and key to fill ratio. At this point I began setting up my render layers, beginning with a ball layer and a shadow layer. By setting up a perspective projection on the ground plane with an image of the clean plate, I was able to add in the bounce light from the ground.
From left to right: original line up over ball background plate, ground bounce light over ball background plate, reworked key to fill ratio over ball background plate, original ball background plate.
Shadow layer.
I also wanted to start developing the asset I am going to have move through the shot. Since yellow is my favorite color, I decided to go with the lemons! I modeled and UV'd the lemon, and then spent some time on look development. I plan to still make a few more tweaks, as I think the color is still slightly off and it feels a bit too glossy.
Look development rig render (HDRI by Greg Zaal from HDRIHaven) vs. Reference (from Unsplash).
1/16/2022: I decided to go back and make a few adjustments to the look development of the lemon to try to make it more accurate to the reference. To finalize the asset, I made these changes:
- Adjusted the base, subsurface, and radius color to give the lemon more warm undertones.
- Adjusted the bump map parameters to make the bumps larger and slightly more prominent.
- Made the surface less glossy by lowering the coat weight in the shader.
- Tweaked the IOR and roughness to get a larger highlight.
- Altered the base color map of the stem to give it more noticeable variation and less saturation.
I also switched out the HDRI from HDRIHaven for the HDR from Sarah's photoset, as I realized it made more sense to put the asset in the lighting closest to what it will be in the final shot.
