A Carcharodontosaurus lurking in the woods

Intro

This is a school assignment from our VFX production course, 3rd year. In this module we had to plan and produce a shot from start to finish. The shot needs to be composed of multiple layers, including CG that integrate with plate. In our preproduction process we had to plan the shoot in detail. This part starts with storyboarding and multiple previz iterations to figure out the composition, action, lighting, camera movement, focal length etc. When I have an approved plan for how I want my shot, I draw a floorplan and book the necessary equipment to shoot.

Preproduction

For this production i decided I wanted to go for a more calm and intimate shot to get variation in my reel. I spent some time this summer creating an asset that I could use, and so I based my idea around using this asset. My main inspiration was taken from jurassic world, where you have shot of the Indominus Rex eye through some ferns and bushes. 

I drew a storyboard based on my reference, but I had a slightly different way I wanted to go, so when I started doing previz I tried out a few different variations. I ended up framing a bit more of my creature.

CG creation

Rigging

For the rigging process I knew I was going to use the asset for other shots that this one, so I set up a complete rig for the whole body. I setup IK constraints on the legs, FK for the arms, and a dynamic joints setup for the tail that responds to the hip movement. Further I set up an eye controller so I can aim the eye where I want. Morph targets are very useful, and I used them to get some facial deformations, awell as eyelid animation. In addition I have an inner layer of eyelid that moves horizontally like some birds and reptiles have. Using sculpt derformers in maya I could have these layers interact with each other, so the inner eyelid will push deform the eyelid, and but the eyelid layers are push deformed by the shape of the eye. 

Filming

I found a location nearby the school that fit my shot idea, so I found a spot with a large branch. Then I found a secondary spot which I thought had a much more interesting background, and I shot a 2nd version where I defocused alot. Originally I wanted to use the defocused plate as the BG, but I defocused to heavy, so I ended up using the sharp plate, and used the defocused plate as reference, which was at the very least very helpful.

For this shot I decided on having a static camera. This dissolved me of having to do matchmoving and I could focus more on the compostiting aspect of the project, however I still needed to align my camera. Therefore I took a photoscan of the foreground branch. This way I could easily orient my camera. 

For my render I needed to get correct bounce light and ambient lighting on my model. This is why I captured a HDRi panorama image of the exact place I was going to place my creature. In my 3D scene i used a few duplicates of the 3D scan i made of the tree trunk, and placed them in various positions around my character. I also used a few planes to guide more bounce light. I also added a separate spotlight with a gobo filter, so I could visualize a gobo effects on the creature. This however doubled the amount of light so I had to adjust the HDRi so I wouldn't get a too intense light.

Compositing

For the compositing part it was important that I had the necessary renderpasses. These will help me adjust the different light properties differently. Say I only wanted to adjust the specular highlights, I can use that pass and grade it down. For instance, I used this pass and changed the hue to match the hue of the highlights in plate. I also used the indirect specular pass to match the hue of the bounce lights more accurately.

When I was on set I also recorded various leaves agianst the sky sky I could key them and use them as out of focus elements in front and behind the creature.

When leyering the different elements, it was very handy to use the position pass. Utilizing this I could position different exactly where I needed them based on distance. Because I had a static camera, this was not strictly necessary for all the elements, but I did use a projection setup for the background and foreground particles. This was important for the particles at the different depth to play well together. The particles should be the same size and speed in 3D space, so when I just put them at different depths I would get realistic size and movement

Lastly I added a gobo effect on the background ferns. I also did some final lens/senser effects like grain (regrain from plate), lensdistortion (only on added elements), and glow