yFX Writes

Supervisors Speak- Train Action Sequence

Lennard Pinto
Feb 18, 2023

The Train sequence starts with Pathaan being escorted to a remote facility after being captured by the Russians. Tiger makes a grand entry to save his life, leading to a spectacularly high octane action sequence between the two spies & the Russians.

Our supervisor, Lennard, takes us through the Pre & Post Visualization process for the Train sequence, spanning over 300visual effects shots!

The train sequence in Pathaan was important as it's the first sequence in the YRF ‘Spy Universe’ of films where we see Tiger making a cameo appearance with Pathaan.

Before this sequence started shooting, we had already put together a pre-viz based off of the storyboards, way back in Dec2020 - That in itself was around a 5 min action sequence after final editing. The final edit in the film - including the end credits scene - was close to 10min!

There were a number of challenges in this sequence, not the least of which was the huge amount of terrain that needed to be generated. This was loosely modelled on Karanlık Canyon in Erzincan Turkey. Seeing as all of the action was in a train moving at significant speed there was a fair amount of terrain to be generated.

 As this was largely a chroma shoot on set - right away, it was important to do a post-viz for everyone to understand the flow of the sequence - This was also needed to lock into place things like travel speed of the train, the major punches and importantly for us, the extent of set build that was needed.

For the purpose of the post-viz we needed to first build and rig the train, then track and match-move the shots before moving onto blocking and preliminary animations.

The post viz itself needed us to generate terrain -For this we used a combination of photogrammetry from some Erzincan plates, Gaea and Quixel megascans. We thought as this was for post-viz purposes, the terrain needed to carry enough detail for the closeup shots to understand the speed, travel and general staging of the scene for all concerned even before final builds

Apart from the terrain build, there were also a few significant punches, including when a chopper gets shot down and crashes onto the bridge taking it out and the subsequent crash of the train into the gorge. All of these needed to be animated and approved by the director before moving into finalizing the same.

 When we finally had a signed-off post-viz (and this process itself took a couple of months from start to finish), we were ready to get into final builds and simulations. We estimated that we'd need about 13 kms of CGI terrain to generate. At first we thought we'd do a photogrammetry capture of the environment to avoid hand sculpting so much area, but as we progressed through the post-viz and based on the live shoot lighting we soon realised that if we went his route, we'd have to customize and rebuild too much of the terrain. Also, we were too close to the mountain for photogrammetry to hold up as the terrain in question was not too accessible.

After some  back and forth we decided this was best to be custom built - using our base post-viz meshes as a guideline, we proceeded to rebuild much of this terrain, using a combination of hand sculpted geo, Gaea meshes and megascan meshes to flesh out the environment. At the end of the day, this all came together pretty well as we had a solid post-viz as a guideline for all.