Low-poly art and the Marketplace

Hi all! I was in a private discussion where people were asking what Epic looks for in low-poly art on the Marketplace, so I put together a short post about the current thinking going into what we look for in low-poly art, and specifically what a great low-poly art pack would contain. I’m going to paste the text of it below, and I’m happy to answer further questions about it as well:

I’m personally a big fan of low-poly art. I’ve been making game art since before Quake 1 and I started out as a character artist, and I’ve done my fair share of environment art as well. Finding the tradeoff between form and function in a realtime environment is awesome, and I’ve spent thousands of hours picking apart my own models as well as the art of others to find out why this edge flips this way to get the right definition and deformation, or how to create strong silhouette while staying within your poly budget, and precisely how, where, and why to cut corners.

However, with the advent of technology, a lot of the real-time performance considerations at this particular level of low-poly art has become more about stylistic choices than boosting framerate on the desktop. And then there’s mobile games, where the art you’re seeing on your phone or tablet today meets or exceeds the best desktop PCs ten years ago. So there’s kind of a split there. We’re also seeing a resurgence of 8-bit and retro-styled games coming in, and low-poly to me is kind of the 3D equivalent to that.

For the Unreal Engine, one of the things it’s always pushed harder than anything else is photorealism. With UE4 getting released, Epic pushing big on PBR and open world and architectural visualization, most of the Marketplace content we’re seeing is building in that direction. Low-poly style stuff is still pretty new and we haven’t seen a lot of it yet, and we’re trying to develop an approach to how we vet and accept content for it.

I want to be very clear that I’m speaking about general guidelines for low-poly art submissions, and NOT about anything specific that anyone has submitted. I’ve been making game art for over half my life and this is an aggregate summary of my observations over the years.

A big part of what makes low-poly art work is that the reason it exists at all is because it was built to meet certain technical requirements. Within those constraints, techniques developed, and a style was born.

Over the years I’ve my fair share of novice artists that think “hey, low-poly is popular and looks easy, I’ll try that!” and create art that’s simply low detail, low-quality, and easy to produce in a short amount of time. They’ll crank it out, think “awesome, I nailed the style!” and feel great about it. Unfortunately there’s a lot more to it than that. Silhouette is important, and so is proper edge flow, consistent polygon size, and distribution of detail based on where the eye will fall. It’s a lot more than just being faster and somewhat easier to produce than high-res, high-end art.

Here’s a checklist of things that are important in low-poly art:

  • Use your edges well. Just because something is faceted and has very few polygons doesn’t mean it’s good. If you’re making a low-poly character, flipping an edge on the face can be the difference between a chiseled cheekbone or a fat face. What does that edge mean, and what does it imply about the overall form and shape of the object it represents?

  • Simplify your shapes, but no simpler than necessary. Understand what the real-world object is that it’s trying to represent, and use your geometry wisely to imply smoothness, roundness, harsh angles, convex and concave surfaces. Again, the entire reason for the low-poly style was because you had to aggressively, constantly reduce polygon count and it forced you to make tough choices. That enforced a special kind of creativity. “Do I lose this edge, or that edge? Is this as good as it could be? Will it hold up at a distance and up close?” One of my favorite examples of simplifying a form that can still be readable and easily understood is Picasso’s reduction of a bull to its simplest form: Animals in Art - Pablo Picasso

  • Consistent level of detail. It looks weird to have a 50 ft tall rock that’s 24 polys, and a 3 ft tall stool that’s 1000 polys. Unless it’s a distant background element, or there are other extenuating circumstances, no real low-poly game would ever be built like that. If you had a strict poly budget and you had to choose where to spend it, the first place you’d start out looking to cut polys is where the eye is least likely to land. That’s why, back in the day, the top half of a character had more detail than the bottom half because that’s what the player looks at the most. Even more from there, in a 3rd person game, you’ll see more detail in the back of the head, shoulders, and butt of a character than on the front in many cases. Find ways to cut corners where people won’t be looking for it. That’s part of why the style developed.

  • With proper construction and with the idea in mind of why low-poly is what it is, consider the market. There aren’t a lot of low-poly packs, and most content for this engine is photorealistic. If you’re developing a game with a low-poly style, and you buy a single content pack that’ll cover maybe one or two parts of a specific style or zone, where is the rest of the art going to come from? If I’m making a game and I buy a low-poly Lava Kit, where is the rest of my game’s content going to come from? I could see if there’s more content of a similar style that I could use, or make it myself, or try to find an artist that will make more, or I can try to take what’s already in this pack and extend it.

I realize this is a bit of a catch-22, but what I’m really saying is that a good low-poly pack will be a) highly modular and able to create a large amount of game content with, and b) have a LOT of content in it. Honestly, low-poly art is much faster to make than current-gen stuff, and I know exactly how much effort goes into it. We’re not looking for limited-scope weekend projects, we’re looking for a broad, modular, useful set of content that game developers can use in a variety of ways across their whole game.

For example, this is what I think a good low-poly asset pack would contain:

  1. Landscapes with multiple features (mountains, hills, rivers, cliffs) built with modularity in mind and multiple materials so you can reuse this across a whole game.

  2. Low-poly modular buildings with single and multiple floors and roofs, set up with good UV layouts you can swap easily or even make new textures for yourself without much effort.

  3. Modular walls and fences that don’t look repetitive. Having some theme-specific ones is good, but think about reusing content across multiple levels with minimal graphical tweaks that won’t be too obvious to a player.

  4. Mobile compatibility. UE4 does actually work on mobile but we don’t have a lot of Marketplace content yet that’s built specifically for mobile. We are extremely interested in mobile content, and are very likely to shine a spotlight on it to get more people using the engine for mobile games. HINT HINT!