MPC Gets Trapped in a Living CG House for Hovis

Hovis believes kids should be outside having adventures but in this dramatic advert, three kids must do everything they can to escape the clutches of a house that will stop at nothing to keep them inside. As they make their exit on bikes, the house flings down building materials that miraculously build themselves into new structures, chasing them down the garden to surround them with brick walls, tile work, windows and doors.

Will they make it out or will the house have its way and keep them trapped in its clutches? To find out, viewers watch as the director Johnny Hardstaff’s unusual commercial unfolds - with the help of the MPC team.

Self-Building

“To get the right feeling for the story the director wanted to tell, we needed to have full control of the way the brick wall was built, what the elements were made of and how they behave,” saidAnthony Bloor, MPC’s head of 3D on the project. “The treatment gave us a good initial idea of how things should look, but it was important to be able to iterate fast and make quick reviews to make sure we were fitting into the agency's and director’s vision.

”To complete the project efficiently, almost all of the walls were built and animated using anentirely procedural system. VFX supervisorAndreu Lucio Archsconceived a way of usingHoudinito lay out all the walls very simply and quickly, and then lay every brick and breezeblock out, employing a plausible construction method. Placing windows and doors then became simple, because the walls would automatically rebuild around these items.”

Then the same system was used to animate the bricks, tumbling into the scene and laying themselves a brick at a time. Back from the front edge, studwork, plasterboard, tiles and wallpaper were all completely procedural, so that animation changes didn’t become a daunting task, even late into the project. With this system the artists had the ability to dial in the parameters and have all the elements automatically placed and modelled with physical accuracy. It allowed enough creative control and artistic fine tuning to achieve director’s vision for each shoot.

Moody Character

For example, the walls have various moods throughout the piece. “At first they are able to build themselves quickly and straight,” said Anthony. “But as the kids try to trick the house, the walls start to twist and turn, getting less perfect and building with more and more random items. Towards the end it’s already wobbling ready to fall over before the final destruction. We also simulated some light dust to help to add realism without excessively covering up the action.

“Thousands of highly detailed models populate the house as it builds through the scene - bricks, breeze blocks, plasterboard, stud-work, tiles and even 1980s style wallpaper. As some of these elements frenetically build behind the leading edge of the construction, they automatically respond to the character of the wall.”

Destructive Finale

Meanwhile, lighting became a challenge due to the continuously changing built environment. A number of practical builds on set during the shoot helped cast shadows and reflections onto the kids - when the house builds over the kids at the start, for instance, a giant set of black out screens were unrolled to change the light from day to night. Then in the shots where the walls close in around the boy in red, a long blue screen corridor was constructed to cast the correct shadows onto him.