The Making of CG Robot “Dennis”, by IXOR

IXOR created a beautiful animation for a TV ad, the star of the show being the robot “Dennis”. We spoke with Andronikos Bisogiannis, Founder & Creative Director at IXOR to find out how it was made.

CG Robot (Protergia 1m55sec TVC Dir. CUT) from IXOR.

Read about the making of the CG robot!

01 IXOR hello!

Tell us a little about IXOR.

I started IXOR in 2005, while finishing my MA degree in Architecture from the University of South Florida. During the first two years it started as a small studio with only 4 fellow CG artists, and we were all delivering highly realistic 3D renderings for architectural purposes at that time.

There is still some work from these days on our website, which is part of our history and we keep it for sentimental reasons as well as part of our proud early steps into the 3D and VFX era 🙂


After just one year we moved into working on product visualization for TV Commercials. We were asked to work on car commercials, and very soon we started merging CG animals and other more complicated FX into moving pictures.

It was not an easy transition I have to admit, but with constant effort and other key people and professional artists joining our team, IXOR grew quite fast.

Currently we are offering high quality VFX and 3D animation services.  The main production house is located in Athens, with a studio office in Los Angeles, and a representation in London.  Our passion and hard work have earned us several awards and accolades from our peers in the international CG community, as well as in internationally known events in the advertising and film world.

IXOR Studio

It is worth mentioning that during 2016, IXOR was nominated for best Visual FX at Sweden’s Guldbaggen Film Awards.  After four intense months of shooting in the Scandinavian landscapes, IXOR was responsible for all the visual effects behind the Swedish feature Film “CIRKELN” (“The Circle”) produced by RMV Film. Awarded all the VFX for the movie, we had the chance to work in more than 300+ shots, including set extensions, fire and smoke, digital doubles and DMPs​.

Although we had used Corona Renderer in the past for simple shots and smaller scale TVC projects, from early 2016 we fully adopted it in our pipeline for larger scale projects. The ease of use and quality of results that our artists can deliver with Corona was more efficient. The difference in speed and how IXOR has been able to overcome various CGI production challenges in various projects has made Corona one of our favorite weapons of choice!

04 IXOR CG Robot Concept
Development concept artwork for Dennis the robot

For the project we are talking about today, IXOR was asked to work on the creation of a cute little robot named Dennis, in a touching tale of a young boy who accidentally left Dennis behind when moving house.

The commercial follows Dennis through city streets, facing all kinds of terrains and situations. The aesthetics for such a project needed to be something unique and our lead concept artist worked on various ideas and drawings.


The compositing in the project is exceptional! What were the challenges, and how did you overcome them?

The task in composition was basically to make Dennis the robot “invisible” as a CGI element. That cute robot, our main CG hero, had been lost in the city, trying to find his way back home where a lovely boy – his owner – was pretty heartbroken at losing him.

It was an emotional story between those characters, and in order to make that story believable, the goal was to accurately integrate the CGI Robot into the footage and let it participate in the story as a “real” living being.

05 IXOR CG Robot Concepts 02

06 IXOR CG Robot Compositing 01

07 IXOR CG Robot Compositing 02Multiple Corona Renderer layers were used during the rendering stage such as lighting, GI, Albedo, Reflections, Refractions, Emission, as well as World Data.

The actual CGI & post production time was 6 weeks in total after shooting. We had to create realistic robotic character animation along with additional FX elements, with moving cameras and some pretty demanding indoor & outdoor shots.

A few shots also required interactions with humans and reactions to practical effects – for example, with the robot inside a box packed for the move, or when the kid is hugging Dennis, or when Dennis is being pulled by a bicycle, etc. Multi-pass composition was the way to go for having control over every lighting attribute, especially when the post production schedule is tight.

08 IXOR CG Robot Render Layers
The layers and passes from Corona Renderer.

HDRs are a “must” when it comes to reflective surfaces, such as the metallic surfaces on the body of Dennis. For accurate lighting, photogrammetry during the VFX supervision was used along with lens grids, lighting & reflection reference with gray and chrome balls and camera / tracking information for each shot.

09 IXOR CG Robot HDRI Capture

The pipeline was to transcode from ARRI raw to 16bit EXR files,  so as to maintain the entire color range that the camera offered. This gave the DOP and our Colorist the ability to grade based on the look they were after.


The ending shots with the boy hugging the robot must have been particularly challenging, how did you achieve that?

This is a common challenge in the VfX industry, and it came up in this project for the shot were the boy hugs Dennis. This kind of shot is always tricky and needs special attention, both in terms of acting as well as how the interaction is happening.

To maintain a high level of believability and keep the audience invested in the story, we recreated the torso of Dennis using a green box, as the boy needed to interact with some sort of physical body or object in order to be able to act properly.

Tracking markers were placed on the green box proxy in order to track the camera motion and then key out the box and replace it with the robot. Additionally we had to create a digital double of the boy and Roto-animate this CGI boy to properly reflect off the robot’s metallic surfaces.

10 IXOR CG Robot Hug 01
The digital double of the boy, to get reflections from the robot’s metal surfaces.
11 IXOR CG Robot Hug 02
The green box proxy on the left, and the final composited shot on the right.


The robot has such a strong personality! What secrets do you have for conveying emotion purely by action when there is no dialogue?

To be honest it comes down to good animation, successful concept design to reveal emotions, as well as a solid rig system. So, no special tricks in this topic! Most of the credits belong to the artists and their talent 🙂

12 IXOR CG Robot Personality Composite

We also used our practical robot to transfer tiny vibrations and other life-like movements to boost the realism. During the development of our CG character, we did various animation emotional tests, as we knew how important this was for the story; Dennis had to deliver acting as if he was the main protagonist. So behavior, feelings as well as expressions and emotions needed to be clearly visible in such a short film duration.

13 IXOR CG Robot Personality 02

Controls for facial expressions were created for each and every single part, separately from the body, giving our animators the freedom to create the acting. There were some automated functions that took place in the rigging, such as a constraint system for the treads so that they not only move automatically in a realistic manner as we move the robot asset in our CG recreated environment, but so that they also deform depending on the ground surface.

Other automated rigging features include the folding parts of the head, the eyes, and the arm of CG Dennis. Additionally, hair simulation was used in order to archive a realistic cable motion as the robot carries out his actions.


What was the workflow for creating storyboards and test renders?

14 IXOR CG Robot Storyboard

15 IXOR CG Robot Storyboard

Prior to storyboarding the script, we wanted to define the scale and character of our robot. It was vital to get the design and look first. For example, a humanoid robot is able to act differently and offers other possibilities than a small, legless toy robot. So the facial characteristics and finding ways to transfer the body language was a challenge right at the early stages of production.

Our 3D team worked along with our concept artist and exchanged many sketches, 3D clay models and test renders to the creative team and Director. Once the final look was approved, we were able to choreograph the shots better, and the storytelling went to the final stage.

16 IXOR CG Robot Storyboard


Why did you choose Corona Renderer for this project?

Starting with the great feature of the fast and accurate Interactive Rendering in the frame buffer, then add in the nice behavior and roll-off of the lights, then the material shading system, and all of that is what makes Corona a great benefit. It combines ease of use and realism.

Our artists focused on creating nice looking imagery instead of troubleshooting and playing with tons of settings. The materials are very user friendly and provide the necessary features to create almost any surface required. It was very nice to have a quick response for look development, and the visual feedback makes for an efficient and artistic workflow – which is a pure joy in VFX and 3D animation productions!

We took HDRi’s for all the shots at day and night, as well as 360 dome recordings using a fisheye camera rig when we had moving lighting conditions, to give exactly the same environment in the 3D space for rendering our CG robot, including having moving reflections.

Photogrammetry was also used to recreate proxy geometries for light blocking, GI bouncing, accurate shadow catching (matte) surfaces, as well as GI color bleeding.

17 IXOR CG Robot HDRIs

It was really fun to play interactively with Corona and move the lights to highlight some specific specularity or diffusion on Dennis the robot; we really enjoyed the nice controls and efficient ways to make adjustments that Corona offers.

18 IXOR CG Robot Dennis Fun


What were the render times involved?

Regarding the render times, we created fast 10-minute draft grainy renders at 2k resolution, so that our lighting and compositor artists could start preparing and assembling the render layers and the composition of individual shots.

The idea was – and still is! – that while our lighting artists are working on finessing the look of each shot, the rest of the team, especially compositors and animators, are progressing in parallel while the final look is still being developed.  Additionally, the render layers offered good flexibility and adjustment control in compositing.

Afterwards, we had to re-render and let Corona cook it in our render farm for a longer period of time, so that we get grain-free results; composition was automatically updated with these final renders, all while our compositors continued their work! That was truly a great and efficient way to work as well as to provide feedback to CGI supervisors and Creative Directors.

Since all render gurus out there love to hear about final render times, let’s share some numbers!  Our average time was 1 hour per frame in a 2k resolution using Dual Xeon systems. I have to admit, I was impressed with the render times!  Flicker free, trouble free and running with no errors.

19 IXOR CG Robot Render Times
IXOR’s in-house Refamo render farm management tool.

For render farm monitoring and debugging we used our in house software Refamo which allows for easy identification and monitoring of the network computers.


What projects are you working on next – anything else that will be using Corona Renderer?

Currently we are involved with two feature film productions with VFX and CGI shots, several TV commercials, and an experimental project.

In some of the above productions we are using Corona, especially when it comes to hard surface elements and other visualization productions. The establishing shot of the feature film “A Beautiful Time Ago” showcasing a full CGI Mediterranean city will also be created with Corona Renderer.

We have also started to adopt Corona Renderer for CG animals and characters. On the other hand, for volumetric effects we are still using other engines, while waiting on the development of new features from Corona’s team to arrive so we can implement those new features in our future productions! We are especially looking forward to custom hair shaders and/or hair plugin implementations, as well as volumetric effects (editors note: many of these are planned for Corona Renderer 1.7).

20 IXOR CG Robot Next Projects

Additionally we are developing short film productions using VR technology for other shows and media. We cannot share too much information yet, but it seems that Corona Renderer is handling these quite well, so will most probably be used there as well!

We are really excited about the overall progress, quality, fast production, support and development from the Corona team and we are excited and glad with the work produced so far.

Keep up the good work!

Andronikos Bisogiannis
Founder & Creative director at IXOR





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