Hi! I'm Guido Ekker and I am a Senior VFX artist and Filmmaker living in Amsterdam, The Netherlands.
Working as Senior Visual Effects Artist for Post Panic. I am closely involved in pre-production and concept development from the start of the commercial or film, with previs and on-set VFX Supervision. In Part 2 of this Process Technique, I'll be talking us through compositing and painting over the scene we set up in Part 1!
Let's get into it!
In the last tutorials article we took a look at how to set up a 3D Maya scene with Redshift for 3D paint over. We followed a specific workflow which allowed us to skip certain steps in 3D and speed up our process for paint over purpose.
I did explain some technical parts but also try to keep it very artist friendly. This way of working I mostly use because it keeps it creative rather than too technical. That way it stays a fun journey! At first we started gathering reference images. They are the key to our texture, lighting but also realism. We will use these combined with higher resolution images to paint over our 3D render. But first we have to combine the AOV’s we rendered from Maya.
"First we have to combine the AOV’s we rendered from Maya."
I always try to maintain as much control over the image without working too destructively but sometimes you just have to, so don't be afraid! Making use of a compositing software allows us to tweak renders afterwards. The passes we sandwich together in compositing to create the final rendered image. If it’s only for a still image then this process can also happen in PS but in this demo I will be using Nuke as my compositing software.
Now we are going to start and combine the passes that we rendered from Redshift. I’ll be merging the passes in "plus" mode starting with our GI (global illumination) and Direct pass. This will give us the base for the lighting of the scene. After that I'll plus in my Specular pass (highlight pass). This one I often tweak, pushing the gain up and cranking the gamma down a touch to make it more visible, based on the reference images. After the Specular I’m again merging the Reflection and Refraction passes in "plus" mode. As for the many windows, they go hand in hand. Last but not least, for this demo I am using the volume light pass to bring in the atmospheres! With the cryptomatte pass you can isolate certain objects so you're able to treat them differently. For instance, changing the specular on the concrete and windows separately. So go ahead and tweak it to your liking!
Now that we tweaked all passes according to our references and visual direction it’s time to render out the image. The settings I am using to render out the image is a 16bit PNG. The bit depth allows us to keep a broader color depth/range in the picture. This will be useful when adjusting the render itself in grading later on.
Now that we have got our Beauty render ready for Photoshop, it’s important to also have a good library of textures. These textures we use for painting over the render but also as a photorealism reference. Let’s take a closer look at our current references, gathered at the start of the demo. These will indicate what we are looking for. There’s a lot of variations in weathering on the building. For that I will be looking for dirt textures and decals. But what I find helps the most, is dirt and weathering that's already photographed on a building, so the scale is correct. Another thing is that there’s heaps of aircons installed on the 3D building, with different brands. Also curtains will help to separate our apartments. Hanging laundry is also one of them, and like in part 1 I am only going to differ in shades as I want them all to have a unified red color to them!
"...it’s important to also have a good library of textures."
Talking about laundry and cloth I am going to hang some bigger pieces of ripped cloth over the city as sort of shades, covering the streets below. So we need some bigger pieces of ripped cloth textures!
Some smoke and dust elements will help us with the variation of the atmosphere in the city. I want to stay in the “zone” of painting as long as possible, without breaking it up for gathering more pictures, but as we paint over the renders, we will probably come up with more elements we need. So for now this library of images is a solid base to start working on the paint over in Photoshop.
Photoshop paint over
The final step! Taking my beauty render into Photoshop together with all the source texture images and start photobashing and painting them into the render.
I'm going to randomize the CG clothes using a simple "lighten mode" technique.
First I wanted to focus on the variety of clothes, breaking those colors a bit with different pictures of hanging laundry, but maintaining the overall red colors.
Using a cut out from one of the texture images I'm going to randomize the CG clothes. A simple technique for this is using the lighten mode. I often use this to blend materials and textures together. For this purpose it will blend my current CG clothes nicely with the photographed textures.
The overall feel of the concrete still stands out to generic and clean. Applying real photographed dirt will add to the realism and feel that we are aiming for. I often selected certain areas of pictures or just an entire building and place them on top of the cg rendered concrete.
Using soft light blending mode, you will be able to preview as if it's integrated. I'm doing this for most open concrete sections. Finding the proper position, playing with your opacity and layer mask. You can do the same with for example decals, sunshades and vegetation. Adding extra weathering to the render.
Our volume light from Redshift also needs some work. We don't have any nuance in there and it feels pretty flat. To break this up I am using smoke images, coming from for example a chimney. Having this on overlay and playing with the layer mask we can bring in the nuance. So the atmosphere feels more polluted.
To make the city bit more vibrant I wanted to also have lights on in the houses. A quick and easy way to do this is to source nighttime pictures of city lights. You can then have these on top of your render by switching the blending mode to Lighten. Now just paint your way through and make it come alive!
It’s getting there now! But I haven't really touched the cloth hanging over the city streets. This is a tricky one as we need to find good stock material for this. For this it’s all about manual cutting out of ripped cloth, scaling and warping, until it fits with the shape of our cg cloth. Here I did not use any blending modes.
Now that all the elements are painted on top of the render it’s time to do some color corrections. With the color corrections we can play to get certain areas darker and make others pop more. Steering the viewer's eye. The tools that I will be using for the grading are: Hue/saturation, exposure, curves and a color balance.
For the saturation, I’m boosting it with +15. To get a bit more color and lose the brown tone. With the exposure, I'll gamma-correct it a touch to get some more contrast back and I’ll do the same with my curves. Darkening the blacks and a bit on the highlights, this will give the image a nice balance and lose the flatness even more.
"As a final step I will add a film noise on top, like it’s been shot with a real camera."
With the color balance I will push the highlights to feel more warm and the shadow to be more cold. The mid-tones are somewhere in between those two. Not too blue, not too red. I’d like to give it a vignette to steer the eye even more. I’ll be doing that with a dark soft brush on very low opacity, just painting in the corners and making a subtle vignette over the image.
As a final step I will add a film noise on top, like it’s been shot with a real camera. This will blend all the layers more together and give some realness to it. For this I am using the soft light blending mode on 55%.
Done and ready to share your work with others!
I hope you enjoyed this demo scene, showing an insight in my 3D paint over workflow. If you have any questions, feel free to contact me! For more of my work and to connect with me visit me below.
~ Guido Ekker