Here is a quick breakdown of a project I completed last year for the film “When Ghost Meets Zombie”. This was a pretty quick project, with a total turn-around time of 8 days, including all R&D and setup of the various cloud elements.
Spoliers: The premise is that the two main actors have died, and are meeting again infront of the gates to heaven. As a side note: Led Zeppelin finally won their law suit today, so Stairway to Heaven is officially theirs, yay! Or at least until another person comes out of the woodwork to sue them again. I degress…
This job consisted of creating a cloud stairway, a vast cloudscape, and a heart-shaped arch for the top of the stairway.
As this was a fast project, the most efficient method would be to split the project into the strengths of myself and the studio, Light & Shadows, who I was contracted with. The plan I set-out was that I would create the assets, and then deliver animated VDB caches that they would then transfer into 3ds Max for final rendering in V-Ray on their renderfarm.
I initially did some tests to create a cloud with realistic break-up of the edges, while giving an overall feel of translucent clouds with light shafts streaming through. This was achieved through SideFX’s Houdini software, using VDB volumes. The client was happy with the look, so I was able to start laying-out larger cloudscapes to use as a base for developing the next stage: the stairway.
A layout scene was provided by the client, which I used to setup the scale and position of the cloud elements that would make up the stairway environment.
During the development of the cloud assets, I sent several test vdb assets to the client, for testing inside of 3ds Max and the V-Ray render. This helped me to dial-in the required voxel resolution, and optimize the assets as much as possible with relation to the screen-size of the clouds. It’s pretty easy to generate insanely huge VDB files, but at the end of the day, it takes too long to render, then this would affect the delivery on an already very tight schedule.
To give the clients the most freedom for the cloud layouts, I generated a set of 14, animated VDB cloud volumes that could be used as individual “blocks” from which to build the overall cloudscape. Additionally, these were used as background-fill elements during the close-up shots, which helped to quickly setup one-off shots that only contained enough VDBs to fill the camera’s view.
Overall, this was a fun, quick project that gave me a good opportunity to delve deeper into Houdini’s volumes.