In our previous post, Andrew Hamilton gave you an introduction to photogrammetry, the history behind the process and its use in game development. In this post, I’ll be covering what we do when we arrive at a location, and how we go about applying photogrammetry in practice.
My first big photogrammetry trip was in late 2013 when I took part in one of the first large game projects that applied photogrammetry broadly to capture complete environments. You can find some examples of the titles I have worked on in the past that leveraged photogrammetry on my ArtStation page.
As Andrew described, a lot has changed since the early days, not only in terms of software but also our approach to the process.
Some things, however, remain the same. The first thing that always strikes me when arriving at a location is how elaborate nature really is. It’s easy to get overwhelmed by the sheer amount of detail of a real biome, which is why it is important to keep a cool head and approach photogrammetry in a systematic fashion.
When arriving at the Teide National Park on Tenerife for our latest photogrammetry trip, we spent most of the first day driving around to scout for different areas with distinct biomes. We made sure to observe how these locations would be affected by changing daylight and shadows to map out the best times to scan them. While we did extensive planning beforehand, seeing the island with our own eyes instantly led to changes to our priorities.
Once we had identified locations that we knew we would spend lots of time capturing, we needed to break down the locations into manageable components. It’s easy to be drawn to that amazing and unique rock structure, when in fact it’s the more mundane and generic rocks or trees that you should focus on first. These are the sort of assets that will be repeated throughout the environment in a game engine.
Here are some examples of what a baseline of biome assets can include.
We always try to break down the biome into a few terrain types and think about layering. If it’s a rocky environment, it usually comes down to a question of granularity, ranging from fine sand to bigger boulders. If it’s a forest, you would focus on building up through its natural layers, from the dirt, ground cover, bushes, to trees.
With a wide range of seemingly generic environment details, from fine detail textures all the way up to massive cliff walls, we will define the base quality of our game world. By making sure that these assets are captured to the highest possible quality, we ensure a high visual quality-bar for the game itself.
Here is an example of a few generic real-time, low-poly 3D assets that we scanned and processed after our trip to Tenerife. It’s a simple set of rocks that will be scattered throughout the environment, that make up the baseline of what you will encounter as you play.
Once we had captured a baseline of content, we began to focus on the unique rocks, interesting dirt paths and other odd and interesting things we noticed, that you wouldn’t necessarily think of without encountering them in real life.
These eye-catching assets add a lot to the final result when layered on top of the base. On our trip to Tenerife, they included walking paths, dried out river beds or just a small natural ledge to break up a generic-looking slope, which will add an extra layer of believable quality to the overall environment impression once in-game.
We also make sure to include an image of a color chart in each scan so that we can ensure a consistent color balance when we recreate the assets in the engine, this will also ensure that the wider array of assets all fit together.
While I’ve been working with photogrammetry for many years now, there is always something new to learn. Here’s a brief recap and some extra pointers:
- Planning is key. Remember to always plan your scanning and your time. Make sure to prepare your trip by researching extensively beforehand, and make sure that the equipment you bring is up for the task.
- Capture the essence of a location. Capturing all the core parts of what makes any particular biome feel unique will make the environment come to life. Rocks will naturally fit within the same family, forests will have a flora that fits the ecosystem, and the individual assets in the environment will combine to make something more than the sum of their parts.
- Capture a lot of reference video and photos. It’s easy to forget to take reference photos and videos of the environment while scanning. These become very valuable when you come home and start to recreate the biomes in engine.
- Always take an image of a color chart with your asset. This will help you color calibrate your assets as you produce them for in engine use, keeping a consistent and true color balance across the asset library.
- Bring good clothes! We walked for many tens of kilometers per day in rugged terrain with temperatures ranging from -3 °C in the morning to +15 °C and a burning hot sun in the noon, so next time I’ll make sure to bring a more varied set of clothes and a good pair of shoes.
In the next and final post, my colleague Robert Berg will let you in on what we do with all the thousands of images we captured, and how we go about getting all this content into our game world.