Hi, my name is Sascha Bähr. In this entry I want to show you 2 of 4 of my Demoreel projects in more detail. The projects were created during my mentorship at Thinktank-online. The focus of these projects is VFX Lighting. The other two projects were created as part of my education at Pixlvisn Media Arts Academy.
Also check out my entry Lighting for 3D animation to see the other two projects of my demoreel in detail.
· camera tracking
· optimate Skull Model (partly retopology, uvs)
· texturing and lookdev
· illustrate some 2D elements (logos, pictograms) for texturing
· model 3D geometry (sticker, some head applications)
As a VFX lighting artist you have to work with given life-action plates. So I wanted to do this project to show that I could handle this kind of workflow.
START / TRACKING A DARK FOOTAGE
After I found and selected the video footage and the model for the integration, I knew that tracking with this kind of footage would be a challenge for me. I liked it very much. But it was very dark, mostly washed out or blurred and had compression marks. This meant that tracking would be very difficult.
To get a better result in Nuke with the camera tracker, I sharpened the image slightly and increased the contrast between the person and the background without making the compression marks too dominant. To achieve an accurate tracking result, I chose a high number for the features and a low distribution of them. These adjustments helped me a lot with the final tracking result. However, minor errors in the tracking appeared in between. I manually compensated for these errors in Maya by adjusting the rotation of the head at the problem areas. In the best case you have tracker points on the person that improve the tracking of dark images.
COMING UP WITH A LITTLE STORY
After the tracking was done, I thought about how I could make the project even more interesting.
Since I had the model of a robot, I thought about doing something similar to what was done in the movies "Short Circuit" or "Chappie". The synthetic human should have got an own consciousness similarly as in the films by a disturbance. The concept was now the "free will".
For this I modeled in ZBrush a sticker for the forehead with the imprint "rejected". A graffity with an anarchy sign and the word "fake" should illustrate a conflict. Furthermore, I designed logos and symbols in Adobe Illustrator for the texturing process in Substance Painter.
MODIFICATE THE MODEL
To focus more on lighting, I downloaded the base model for free from scetchfab (credits in the demo reel). Since the entire model was made of triangles and not beveled, I decided to retopologize the larger elements (head, eyes) to have more control with maps later in the texturing process.
To make the model look more realistic and interesting in light and shadow, I added smaller applications to the model and worked a lot with displacement and bump maps.
LIGHTING IN MAYA
First, I added a simple gray shader to the model and imported it into Maya for reference. Then I roughly created the lighting. Without existing texturing I could see if there would be interesting shadows or if the model would look too simple at the end.
In the next step I created a cylinder for the first light and adjusted it to the size of the glow neon tube from the footage. After that I created 3 area lights and adjusted them to the position of the neon tube. The neon tube could now shine to all sides except the back. In this case, the back was not necessary because there was nothing to expose in the background. Since the surface was less shiny, 3 area lights were enough to give the impression of a glowing neon tube. More lights would have increased the render time unnecessarily at this point.
Once the area lights were in place, I was able to parent them to the cylinder and use it to control the animations. The cylinder has been rendered invisible so that it is not visible in any reflection.
In the next step I placed a skydome with a simple HDRI from an old warehouse. I adapted the HDRI to the existing colors of the background room with a color correct node. Now I was able to control the basic brightness of the room with the skydome I had created.
After all the lights were placed I built some geometry to use as a shadow blocker. Most important were the body and the collar. These have the function of blocking the light sources and at the same time were used to project the footage to give the head the right color cast.
RENDERINGAfter the lights were placed and ready, I prepared the required AOVs and set the render setup.
For control I checked again the set values for the Ray Depth in the render settings. To avoid unnecessary reflections, I went through the number of light reflections needed for the surface-comlexed objects in the scene. After some render tests with a small number of frames I was able to determine the optimal number of samples and lightsamples.
POST PROCESSING/ FINAL TOUCHESAfter retouching out the visible hair with the Rotopaint node, bringing all the elements together was not particularly difficult. The trickiest part was to create the shadow of the head for the clothing using the Roto-node. For this I watched some videos and tested the light/shadow behavior of different surfaces like leather at home. Normally, the shadow is created using a shadow catcher. But because the tracking wasn't 100% accurate, I couldn't use the shadow catcher. Due to the effort involved, I decided to create the shadows differently.
The head felt more and more integrated when I adjusted the Z-Defocus setting to the footage. Next steps were color grading and adding some motionblur. Then I created a grain map and adjusted it to the footage to match the integration to the compression of the footage.
Final steps were adding godrays for the eyes, which I rendered from Maya, and using lensflare effects to make the eyes glow more. As a final step, I made the black values a bit darker to create a more menacing mood. I also used various vignettes to draw the viewer's focus a bit more to the head.
I learned a lot from the car project "Sunside ride" that I created before. I was able to apply a lot of what I learned there to speed up my workflow for this project.
The most difficult part of this project was the tracking, because in the best case you have tracker points on very dark footages, which simplify the workflow. From my current perspective, the footage may have been a little too heavy for me when I started the project. It's always good to allow a little more time for unexpected problems, but I learned a lot on this project about finding solutions away from my regular workflow.
· texturing/lookdev/uvs of the car
· creating skydome, reflections, projections
· animation of the car
As a VFX lighting artist you have to integrate 3d objects to a given footage. For my first integration project in VFX I wanted to have the focus on the technology and learning the VFX workflow.
START / TEXTURING, LOOKDEV OF THE CAR
This is my first project created as part of my mentorship at Thinktank. The car, the Acura NSX, was purchased to save time on modeling (credits in demo reel).
To make the scene as realistic as possible, it was clear from the beginning that the car had to be reshaded and textured. Since the car had already been driven several miles, it had to have an appropriate level of dirt. For the style, I looked at many different references and thought about the aerodynamics of the wind and how it would disperse the dirt through splashes and dust.
The next step was matchmoving. Since I didn't know the focal length and other background image information, I determined the correct camera settings using the Camera Tracker in Nuke.
When creating the geometry, I divided the scene into shadow catchers, shadow casters, and projections early on. The row of trees on the left, for example, didn't need geometry. For this, I searched for suitable royalty-free tree images, which I then croped and color processed in Photoshop.
Another important step was to reconstruct the shadows on the street. I drew the shadow line on the footage at the beginning, so that it was easier for me to match the shadows in Maya.
LIGHTING / RENDERINGAfter the matchmoving was done, I started with the lighting. I used a Directional Light to set the main light source. Then I adjusted the position, brightness, rotation and the angle to the footage in the background.
Because I hadn't photographed the background myself, I didn't have any individual images of the surroundings that I could assemble into a skydome. After several approaches, I decided to use the existing footage as the basis for the skydome and retouch the rest of the information in Photoshop. Since the car was not highly reflective, the retouching was mainly about having the right colors in the right place. Strong brightness points that were in competition with the directional light I had retouched out in this step. If I had wanted higher quality ambient reflections, I would have photographed a similar backdrop and assembled it into a skydome.
The trees were placed on planes and distributed as an avenue as in the footage. Here it was important that the treetops are properly reflected on the windshield of the car.
To have full control later in Nuke, I created 7 render layers with the render setup in Maya. Especially with the shadows for the car this process was very helpful.
POST PROCESSING/ FINAL TOUCHESGET THE CAR SHADOWS RIGHT
After bringing all the elements together in Nuke, I was first thinking about how to realistically add the long shadow from the car with the shadows from the trees.
GRADING / DEPTH
Since the car now casts a merged shadow, I darkened the right side of the car a bit to match the color of the Shadow plate.
For each 3d-element I created a grade node which should control the atmosphere. With a few more adjustments I was able to quickly adjust the colors at any time.
The next step was to blur each element with the correct depth of field setting.
After color matching, I created a series of planes in Nuke. A smoke footage is intigrated in each plane. The planes appear on coordinated frames as the car passes. I used many planes of smoke footage to create a seamless look and avoid visual holes.
Next step were adding some motionblur. Then I created a grain map and adjusted it to the footage to match the integration to the compression of the footage.
In the global color processing, I wanted to make the overall look a little fresher and more summery. An animated flare node supports the incidence of sunlight from the corner of the eye. While different vignettes should put the focus on the car.
The sunside ride project was my first VFX lighting project and I learned a lot from it.
Already at the beginning of the project I knew that the project would be technically more challenging than anything I had done before. And that was a good thing, because I definitely wanted to handle complicated tasks.
For the first time I had enough time towards the end to take care of existing problems and to further optimize the result. Having enough free buffer at the end of a project helped me a lot here.
Thank youThanks to everyone who supported me during my time at Pixlvisn and Thinktank. Special thanks to Brandon Martin as well as Stefanie Knopp who provided me with feedback along this journey.
Also thank you for taking the time to read my entry. If you have any questions please feel free to contact me.