LogInMarco Catena, the Co-Founder of PropHaus, discussed the asset store's origins, gave a detailed overview of his production process, and offered advice for aspiring asset merchants.
Introduction
I'm Marco Catena, a 3D Artist and Co-Founder of PropHaus. Primarily, I create 3D assets for Unreal Engine, specialising in modular buildings and environments which are published and sold on Fab for creators, hobbyists, and enthusiasts.
I began developing PropHaus in 2020 with a friend of mine, Serkan Karaköse, as at the time, our current project was slowing down. We were working remotely with an indie studio on a game using CryEngine called Miscreated. This was a live-service, multiplayer survival title released on Steam. As it was proving difficult to find new jobs within the industry, and we had previously bought assets for Miscreated on the Unreal Engine Marketplace, I considered the possibility of making a living from selling assets. Even though it was unclear how to break into this market, as there was little information on how to be successful, we gave it a go.
On Miscreated, I was a Level Designer and Serkan was a 3D Artist. Personally, I wasn't proficient at 3D modeling, however, I had spent a lot of time with the art team and learned a lot from them. I loved crafting worlds in the editor for players to run around in, which is the main reason why we focus more on environment art rather than props or anything else.
On our first project, Convenience Store, I created the 2D elements for the textures, such as the fake branding on the signs and shop items. I was also responsible for designing the modular pieces and setting up the showcase levels. It was around this time that I learned to use Blender for future projects.
By March 2023, my work partner Serkan had moved on from PropHaus to work at Hugo Boss as a 3D Artist, so the more recent PropHaus projects have been entirely my own creations.
Unreal Engine
My experience with Unreal Engine has been great! Compared to CryEngine, I do find that there are answers for almost anything you can think of online, as it is a well-documented piece of software. Originally, our environments were built in Unreal Engine 4 using baked lighting, which proved to be a little bit of a transitional phase for us coming from CryEngine, which used real-time lighting. This is another reason why I welcome the newer features in Unreal Engine 5, like Lumen, which allows for high-quality, real-time lighting.
As previously mentioned, another modelling package I use is Blender. I absolutely love Blender! It has become my 3D software of choice for many reasons; it is free, and it is very easy to find resources online to learn how to use it.
I also use Marmoset Toolbag to bake textures such as Normal Maps, Ambient Occlusion, and Curvature Maps. As a texture baker, it is super simple and inexpensive. From this, I create textures inside Adobe Substance 3D Painter, which I just find very intuitive to use due to its large and diverse material library.
Breakdown: The Production Pipeline
City Streets was a huge project for me personally. I always start with a few ideas on what environment I want to create; these projects can take over six months to produce, so I need to pick something I'd enjoy. I do some surface-level research to see what products are similar, and I ask myself a few questions: Can I make something better than what exists already? Is this corner of the market already dominated? What value can I add? Do people even want this? For me, this is an important step because it is a huge time commitment that I will be undertaking, it also needs to be worthwhile in the end and sell.
I construct mainly American-inspired buildings, but I live in a small town in the heart of England, so I cannot easily just go and visit these places in person. Once I have an idea of what I want to create, I collect references from various sources. In addition to this, I location scout on Google Maps and make use of their Street View tool. I can explore places that I can base my work off; it is a really good resource when you want to create buildings as you can walk all the way around them.
Google Earth 3D viewer is also a valuable tool, as you can see the layouts of the buildings in more detail; it is the next best thing to actually traveling to a location. I also search online on how buildings are constructed, download manufacturing catalogues for details like windows and doors. These are made differently in the US compared to the UK, but the idea is to try and make it as authentic as possible, and that starts with research and reference collecting.
Once I have the references and a general idea of what buildings I want to construct, I need to then design the modular pieces so they work on Unreal Engine's grid snapping. To get an overall size and feeling of the buildings, I begin with large basic shapes, and from the references, I take common features and deconstruct them into smaller repeatable pieces that I can use multiple times.
I'll start by creating crude, blockout versions of these pieces as templates and use them in-engine to construct a complete building. As everything needs to follow the grid snapping, they all need to have the same 'rules' so any piece can go together, almost like a LEGO set. This applies to both the exterior and interior pieces.
Interiors can be a little tricky, but I create an inside version of the windows, doors, and wall pieces that snap to their exterior counterpart on the same pivot point. There is then a set of partition walls that divide the interiors into rooms. These get more complex with stairs and internal doors. The floor and ceilings are basic planes that also snap on the grid.
Once I am happy with these, I can then create more detailed versions of them as final assets. For wall faces, I use tileable textures to ensure pieces connected together create a seamless texture. In conjunction, I construct trim sheets for things like window frames so I can recycle textures and elements across a lot of my buildings. This is better for performance and also makes my life easier than creating unique assets and textures over and over again. I construct all of the models in Blender, do any necessary baking in Marmoset Toolbag, for example, the trim sheets, and take them all into Substance 3D Painter for texturing.
I am generally a bit more liberal with my polycounts thanks to Unreal Engine 5 and Nanite. The use of bevelled edges and weighted normals is more commonly used on my assets because of it. I find that you get nicer edge details using this method inside the engine than traditionally baking bevels into the normal maps with hard edges. Furthermore, you can get away with more complex and smoother curves on rounded objects. I don't go absolutely overboard with polycount to the point where it's absurd, but I try to remove a lot of the edges that you'd typically consider 'gamey'. It allows for a step closer to realism, and you get much higher quality meshes as a result.
Unreal Engine 5 has provided a robust real-time lighting solution through Lumen, which offers high-quality global illumination and advanced ray tracing, removing the necessity of baked lighting. Though I still include the possibility of the use of baked maps, I no longer provide a baked lightmap version of my projects because with real-time lighting, I get instant feedback on what the overall tone and feeling of the environment will look like. I typically test out a range of lighting conditions until I find what best showcases these assets. I find using an HDRI the easiest way to get a realistic lighting result in Unreal Engine of which you can download commercial-free from Poly Haven.
The example maps or showcase maps I create for all of the promotional material and videos are ongoing from the beginning of the project. From the block-out stage, I am already constructing the map, deciding which buildings go where, and setting up cameras to see what kind of compositions I can get to show off for the final product. This process is constantly evolving as my project develops.
Towards the end of a project, I go around and detail every aspect of the map to dress it up as much as possible. A process I like to call "rolling it in glitter". This is the layers of extra detail and small props that make the environments look more alive and realistic. On their own, the naked modular buildings can look very bland – adding decals, texture variations, and small props on and around them helps ground the piece and tie everything together.
Once all of these steps are completed (and I haven't even touched on the more technical aspects, such as collision primitives, I won't bore you), I start on the promotional content: Creating screenshots and, famously, a promotional video. The video is entirely edited and rendered using Unreal Engine's Sequencer. This is the cinematic editor for Unreal Engine and is a great way to edit the entire video without relying on video editing software.
Typically, I spend around six months on a project, these are large projects to take on as a solo artist. I have to manage and do every aspect of the production pipeline, including all of the promotional material, social media, advertising, and ongoing technical support. This also includes the upkeeping of my previous works and the bureaucracy of running a business in the UK.
As for optimisation and ensuring the assets are game-ready, as I touched on previously, the efficient use of textures is a top priority. Using tileable textures and trim sheets for a lot of the assets reduces the texture memory footprint as they can be reused across the entire environment. As well as this, I pack texture maps for Roughness, Metal, and AO. To keep static mesh instances down, I reuse and repeat modular pieces and try to use the same master material for most of the assets. Making material instances from these master materials, and in some cases parents from these instances, is better for the performance of the scene overall. This is standardised across all of my packs.
I tend to keep my showcase environments quite raw so people can deconstruct them easily to see how I created the buildings by using the modular pieces. I also provide the highest quality textures possible for the user so they can tailor what quality level they need for their project. So in theory, I could optimise my environments even more so by reducing texture resolutions and packing the buildings into instanced actors. These are all relatively easy things the user can do to suit their project. It is important that I provide readability and flexibility where I can for the users of the product. The end user is always at the forefront of my mind when I make these packs, as this is the entire purpose, to serve them across many different project types.
Selling Assets on Fab
Overall, I think the Fab platform has been beneficial to merchants like myself, I am glad that the team at Epic is listening to the feedback to improve the overall experience for both sellers and customers. The introduction of improved search features, licence tiers, and much more has made the platform stronger. I believe there is more ambition here to improve the platform beyond what seemed like a very stagnant Unreal Engine Marketplace that came before it.
Conclusion
My advice for aspiring asset sellers is to make sure you have fun creating your assets, as these can take a long time to produce, you're more likely to finish them to a high standard when you're passionate about it. I would also focus on your strengths and explore what is already out on the market before producing anything, make sure there is a desire for it. You should show off your work on social media platforms so you’re more discoverable. I share a lot of work-in-progress images and videos on Twitter and other social media sites to reach potential customers. It is also a great way to connect with other creators.
It is possible to make a living from this like I do, but be realistic with your financial situation first. I say this as there isn't much financial security in this line of work, you don't get paid for what you're working on, and you only get paid for what you have completed. Even then, the payouts can fluctuate, so you need to ask yourself, are you comfortable with this financially? It took me a couple of years of full-time work on this, burning through savings to get to where I am now, but honestly, I couldn't imagine myself doing anything else.