Week 9 - Monday: Debris Simulation

After reading up on how I can better utilise the mise-en-scene of my environment, I decided that I wanted to exaggerate the level of decay that the mansion has fallen into. To do this I came up with a way for quickly adding a large amount of debris to my scene, which I have implemented within my environment today.

Simulating the Debris

Before starting I had two factors to consider. The first was time. This would be how long it would take for me to populate the scene with all the debris that I wanted to include. The second factor was object placement. This would be to make sure that the debris was placed logically and looked natural within the environment.

I could have chosen to spend a lot of time placing objects in my scene manually by eye, but that would have wasted precious hours. Conversely I could have placed things in the scene quickly without much consideration for the logical placement of objects, but that would result in an illogical mess that would look somewhat fake.

The last few weeks of my major project plan.

Because this is the beginning of week nine and I only have three weeks remaining to complete the environment, I decided that time was the most important factor at play. I had the idea to use the Mass FX tool within 3Ds Max to simulate the falling of debris within my scene. By simulating falling objects in the environment like this I could make the debris placement look natural whilst saving myself a LOT of time.

First I had to test whether this technique would work for my purposes. To experiment with my idea, I created a dummy scene with simple box geometry and applied physics to each box. You can see the result of this test below.

Mass FX simple box geometry simulation.

As you can see this was both a quick and realistic way of creating a mess. The boxes fall in a convincing manner resulting in a more natural placement of the objects than I would have been able to achieve if I had tried to place them within my scene by eye.

The beauty of this setup is that I can choose to add more or less objects to the simulation and this will affect the final result of the debris being scattered across the environment.

Once I was satisfied that the simulation was going to work, I created some assets to use as debris. The objects are all using the same texture, making it easy for me to add further details to the material in Unreal Engine. I intend to add a layer of dust to the objects which will only affect the top facing surfaces of the models. This will help break up repetition, as multiple bricks will have dust covering them at a different angle from one another.

 My fully textured debris assets as seen in Substance Painter.

Below you can see the wireframes of the assets. I tried to keep them low poly but high enough so that their silhouettes would still look good.

 The wireframes of the debris assets.

I applied physics to the objects and then created a dummy scene so that I could quickly simulate the objects falling onto each other.

The end result of the Mass FX simulation.

A close up of the debris. You can see how organic the placement of the objects is.

I ran the simulation a few times and once I was happy with the final output I baked the final debris into static geometry and exported it out of 3DS Max into Unreal Engine.

The debris model in my scene within Unreal Engine. I added some additional leaves to the floor as a texture with an opacity mask.

I am pleased with the end result as I feel already this is making the abandoned mansion feel far more authentic. I would like to continue to layer up the floor with additional dirt masks and other bits of debris.

I think it was absolutely worth expending a little extra time experimenting with mass FX simulations as now I can use this technique again and can potentially speed up my workflow by a large amount.