Plug Effects' photogrammetry masterpiece for Smurfs 2

We are delighted to present this masterpiece of photogrammetry achieved by the artists at Plug Effects. The French studio was in charge of the flying ride sequence around Notre-Dame cathedral in Paris for the movie Smurfs 2.

During the ride, the Smurfette and the Naughties are flying towards Notre-Dame and keep slaloming amongst the arches of the cathedral.

The ride was impossible to shoot live for two reasons:

  • it is forbidden by law to fly over Paris as a matter of safety, so the flight towards the cathedral needed VFX in order to exist
  • the slalom part of the ride required impossible moves for a real camera

So the whole shot had to be CG and requested the creation of a full 3D environment, including the massive cathedral and all the houses, bridges and other buildings surrounding the monument because the height of the flight made almost all of them visible in the shot.

The following video shows both the final shot and the breakdown of the photogrammetry part done by Plug Effects. The birds, the Smurfette and the Naughties were created and animated by Sony Pictures Imageworks artists.

Preliminary test : pinpoint accuracy even shot from a far distance

Because a large part of the Smurfs 2 movie takes place in Paris, both Sony Pictures Imageworks VFX supervisor Rich Hoover and VFX producer Maricel Pagulayan traveled to the French capital for location scouting. They also wanted to visit a selected list of French VFX studios they considered able to reach the quality they are aiming for a Sony Pictures production. Plug Effects was in this selection.

During the pitch, Plug Effects VFX supervisor Laurens Ehrmann and VFX producer Nicolas Bonnell decided to clearly explain the method they would use if their company was awarded the job. They would use photogrammetry techniques with Enwaii software as the backbone of their pipeline, as they already did for several jobs including Ducobu, Paris bords de Seine or Paris a tout prix.

Plug Effects founders and artists are no beginners in photogrammetry, but the best way to prove their talent and the accuracy of the software they chose for their pipeline was to recreate a part of the cathedral facade as a test.

The following screenshots show the accuracy they were able to achieve with Enwaii, even using shots taken from a far distance. It convinced the Sony team that the French studio and its photogrammetry approach were the right choices for the job.

The cathedral reconstruction

The shots were taken with a mix of Canon and Nikon DSLR. The team in charge of the photography took several hundreds of photos to make sure they would get all the data they needed for the VFX. Once the shots were finished they converted the RAW photos to OpenEXR files with Enwashot.

Once the pictures were converted each artist selected the pictures they wanted to calibrate for the reconstruction using Enwasculpt. Some pictures were general overviews to help mainly for modeling, others were close shots required for detailed texturing.

The 4 main artists in charge of the job were :

  • Laurens Ehrmann who was both in charge of the supervision and of all the Paris surroundings creation
  • Nolwenn Rimbault who took care of carefully recreating the cathedral complex facade
  • Eddy Richard who was responsible for the side of the cathedral in all details
  • Cyril Tchernomordik who helped his colleagues in the first stages of the production, specially for the camera calibration task

Both modeling and texturing required to be executed with all details possible because the birds are flying through the structure of the monument. The modular approach of Enwaii and specially the integration of the Enwasculpt module in Maya enabled Plug Effects to use Enwaii as a backbone of their photogrammetry pipeline without giving up all the tools and tricks they gathered during years of experience in photogrammetry productions.

During the production, Plug Effects artists gave precious feedback about every step of the Enwaii pipeline in order to keep improving the software. Thanks to this feedback, Banzai Pipeline Ltd developers were able to keep improving Enwashot, Enwasculpt and Enwamap to make the Enwaii pipeline as smooth as possible for this challenging task and for every future job using Enwaii.

Here are some screenshoots illustrating the accuracy and the complexity of the work executed by Plug Effects.

Images courtesy of Plug Effects, Sony Pictures Imageworks and Sony Pictures.

We would like to thank these companies for the material provided.