Tests de moteurs de rendu, par Mac Guff

For the French movie Gaston Lagaffe, Mac Guff created the VFX of about 150 shots, including the animals of the movie such as Gaston’s cat.

Since Gaston Lagaffe hasn’t been released yet, it is still a little bit early to talk about the visual effects themselves.

Mac Guff compared several renderers in order to choose the best one for this movie.

The studio also shared with us a video with some of those trials. You will therefore be able to form your own opinion using a blind test.

Carine Gillet : Hello 3DVF, thanks for inviting us. I’m a supervisor at Mac Guff. My specialties are rendering and lighting, but I have a generalist background too : therefore I can work on VFX projects that involve either 2D or full CG work.
On Gaston Lagaffe, I’m in charge of the CG part.

Yann Blondel : It’s a pleasure to answer your questions. I’m a VFX Supervisor. I usually work on movies from the script all the way to the Digital Cinema Package (DCP), including shooting and post-production. My role varies at each step, but there’s always the same idea : to act as the interface.

Carine Gillet : V-Ray is easy do apprehend, with a « turnkey solution » approach. For a studio like Macguff, with projects ranging from advertisement to documentary and feature film, it is well adapted. There are tools focused on optimization, baking etc, that really make it « ready to use » tool.

Yann Blondel : We moved away from an internal renderer. We tried V-Ray on a few projects (mostly ads) and we really liked the results, so we switched all our productions to V-Ray.

Carine Gillet : We also did some tests with Clarisse.
At the beginning of 2017, Macguff began working on Gaston Lagaffe, a very complex project. We had to rethink our tools and pipeline. The project involves realistic creatures that are almost « digital doubles », with millions of hairs and feathers. Very early on, before I joined the project, Yann asked himself how we would be able to render those animals. There are several renderers on the market, and even if they’re getting closer and closer from one another, they have different strenghths. As soon as I joined the project in january, this was my first task. Yann bought a 3D model online to launch some tests, we quickly groomed the model, created the same environment in each renderer and began comparing the tools, focusing on what would be needed later on, on the project itself. We needed a renderer that could handle without too much hassle very heavy scenes.

Carine Gillet : They have a very good reputation when it comes to fur, and it shows on the big screen.

Yann Blondel : Choosing a software is linked both to features and the number of users. When you have to use 10 or 50 render workstations, the renderer has to be quite widely used, or easy to dive into. We chose Arnold because it became a standard, and RenderMan because it’s « The Father of All Renderers » when it comes to fur.

Carine Gillet : We created 4 basic similar scenes. Same model, same groom. Then we created the same environment in each renderer, with the shaders and lights available in each of them. We rendered those scenes on the same workstations, then we compared everything : how easy it was to use, shaders, light, how fast it was to use them, optimizations, render times, noise management, how well they could fit in a workflow, how much development we would need to get what we wanted, and of course the quality of the final render.

Yann Blondel : We also did a blind test within the studio with all those rendered images, and asked everyone which one was the more realistic and natural. It was really interesting to get the feelings of a whole group of people.

Carine Gillet : The Houdini/RenderMan bridge, for example with abc and vdb file formats. And the way RenderMan is integrated within Maya.

A mid-sized studio such as Mac Guff typically used Maya as a hub to gather assets created by different software and tasks. The renderer should therefore be as adaptable as possible. Dur to the current limitations highlighted by Carine, RenderMan can still be a little bit intimidating for small studios/boutiques. And that’s a shame, because RenderMan is a real production renderer. It can take in a huge amount of data and is very stable.

3DVF : What results were you expecting to get ?

Carine Gillet : We thought either Arnold or RenderMan would win. Actually, we were quite surprised in the end : we managed to get nice renders with V-Ray.

Yann Blondel : Indeed, many people found our V-Ray renders more natural-looking than what we got with Arnold. It was really surprising.

ann Blondel : The main difference was not about render times, but how each renderer handled light. Compared to V-Ray and Arnold, RenderMan really did a wonderful job (with real focus spots and rim lights). With Arnold and V-Ray, our renders were duller, with a more diffused light.
There was also a big difference when it comes to « softness » and readability on white areas.

3DVF : Could you sum up you feelings about those three renderers ?

Carine Gillet : The tests were made in january of 2017, so quite some time ago. V-Ray, Arnold, RenderMan each have strengths and weakenesses. For our project, the real issue was fur, and the renderer that really convinced us was RenderMan. From a technical point of view he offered more possibilities, and from a visual point of view our raw renders were closer to what we wanted to achieve. We also knew we would have to handle white hair, and this is something we included early on in our tests.

3DVF : You also did some tests using Clarisse : what do you think of it ?

Carine Gillet : It’s an interesting approach, especially for heavy environement scenes. But when it comes to fur, it wasn’t compatible with our workflow and tools on this project.

Yann Blondel : We were impressed by how much instances and polygons Clarisse can handle. Therefore we thought we might be able to use it for hair. Unfortunately, we had issues when using it with Yeti, and we didn’t have enough time to solve them.

Carine Gillet : We chose RenderMan for this project, but we also kept V-Ray for some other ongoing projects. We’re considering using RenderMan for some of our future projects.

Yann Blondel : I don’t know the long term strategy of Mac Guff, but RenderMan convinced me. As a VFX Supervisor I find this renderer brings a lavishness to the picture (for example when it comes to light realism).

3DVF : Thank you both for your feedback !

– Mac Guff‘s official website ;

– Gaston Lagaffe will be realeased on April 4th in France ;

– Progiss‘ website (3DVF partner and Pixar’s RenderMan reseller in France).