Unreal (& Sketchup) in the architectural design process

I recently started using the Unreal Engine during the design stages in the architectural design process. In the design stages, you are investigating interesting design options. Photo-real quality is not needed - it’s all about getting the right space, light, views, composition etc.

Using Unreal, even with just a few textures assigned, the space, light and general atmosphere of the individual design options are much more clear to anyone involved. Also the ability to freely look and walk around in the designs really helps.

The going back and forth between sketches, roughly massing in SketchUp and reviewing the most promising options in Unreal is really fast once you have some sort of a process worked out.

In conclusion: a BIG thanks to the people at Epic for creating a wonderful tool that assists in the architectural design process!

cheers, Max


looks promising!..hope to see soon some aupdate.
The second image has got a great mood, some information on how you have reached it?


Thanks, will do.

The second image is a concept design for a loft - an old concrete factory that has been transformed to lofts.

By adding some IES lights on the walls, the old concrete patterns are highlighted. I just tweaked the light intensity until I got the desired soft effect.

In contrast to the raw concrete I added a wooden floor. The bounced yellowish light of the floor already added a lot. Also, some curtains were added with some lights to add more soft elements.

I wanted to create a late evening setting so the directional sun is rotated almost 45 degree upwards with an light orange color (streetlights maybe) and very low intensity. The skylight has a light blue-ish color and also set to a low intensity.

Some contrasting color (blue) was introduced by the small sideboard in the back. Again added a small IES spot for some effect.

A warm LUT was used to further enhance the atmosphere of image.

It’s just playing around and trying out a lot. There are no magic settings that will always work. It helps to keep your calculation times low by making a (temporary) copy of your complete level and delete everything but the objects you want to tweak.

Here’s some grabbed video (beware: shaky cam) of a real time walk through unreal loft test2 - YouTube

Cheers, Max

thanks for the informations maxbrown,
I think that a great improvement for the realism of your scene will be given from the materials, you have to push they little further (seems not bump or specular at all).


Thanks for the suggestions Paolo. Will look into it.
For the moment though, as I described in my first post, realism isn’t my goal. I use the Engine to communicate the space, light and general atmosphere of the individual design options.
cheers, Max

Hey Max, that looks really great. I’m impressed with how well you’ve done this, and UE4 really seems like an asset to us architects.

I myself am trying to get into using it as a rendering tool. I would really appreciate it if you could give my some info on how you were able to do this. I see you use SketchUp, but what was the process you followed? I use Revit and a little SketchUp, and am looking to see how to do some awesome work such as you have done.

Hello Renzor, you’re right; UE4 really is a great asset to architects.

Here are some steps I use to get from SketchUp to Unreal. Still new to UE, so still trying to improve the process.

  1. In SketchUp my model is created from logical elements (groups). In the loft example above I have: walls, floor, ceiling, ventilation, stairs etc. They are all combined into one component with it’s axis (origin point) set at 0,0,0. This component forces everything to import with its origin at 0,0,0 in UE4
    I also have another component with its axis set at 0,0,0 with the exterior (plane on the other side of the street, some trees in earlier versions etc).

  2. everything (all faces in the groups) is textured: they have a material with a texture on them and the according mapping size you want it to have in UE4 (see below, point 5).

  3. every single group is exported as a separate fbx file. By doing so, you can change something in one element and reimport only that element in UE4. If you would combine the whole model into one fbx file, the sub-material order (the way the materials are assigned to the individual elements) might change and you would have to redo all materials again in UE4 if you would reimport that file.

  4. In UE4, import the individual fbx files. Choose <generate lightmap UVs>, don’t import the materials and textures. Once you have done a few tests / projects in UE4 you will have set up a nice UE material library with far superior materials and will re-use those so no need to import the SketchUp materials.

Short explanation about the <generate Lightmap UVs> : SketchUp’s mapping capabilities are very limited and it has (even with plugins) no way to create a second UV channel that Unreal needs to store it lightmaps. For simple models you want to enable Unreal to auto-create the lightmap UV’s (=copy & re-arrange the UV’s for the material). That’s why you have to assign a material with a texture(!) to the faces so it stores mapping UV’s (see above, point 2)

  1. select all the imported meshes and drag them into the main viewport. In the right pane, under the <Transform> section, click on the yellow arrow next to the <location> so it resets them at 0,0,0. This way, everything you import later will line up at the same origin point. (reason for above point 1 - combine the groups into one main component).

7 if you don’t have some nice materials yet in UE, click and drag your texture files into the <content browser>. Right click on a texture file and <create material>. There are several good videos on youtube about creating those.

  1. in the content browser, one by one right click on the imported meshes and choose <edit>. Assign the materials to the individual sub-elements. By applying them here, if you reimport that element later, it will keep the settings.
    Scroll below and expand the <build settings>. Change the <Min Lightmap resolution> according to the size of the object. Keep the values low at start for fast testing. Once you’re happy with the overall mood - make them higher.
    Scroll below and look for <Static Mesh Settings>. Set the same value at <Light Map Resolution>

  2. Add lighting and build the lightmap. More high poly objects will throw errors due to overlapping Lightmap UV’s. In that case, just increase the lightmap resolution for those objects (also a reason for 2).

If you exported highpoly objects (for instance furniture with curved surfaces) to Unreal, the auto-create of the lightmap UV’s will most likely fail, even at high lightmap settings, and you will have to use program like 3dStudioMax/Maya/Blender to make proper UV’s.

Learning uv mapping in Blender (or one of the others) might be a good choice anyway because if you make the Lightmaps yourself in Blender, you can optimize the UV’s and upscale the area for the more important parts of the objects and downscale the UV’s for the parts that will be hidden anyway.

  1. start small with the most important elements and work from that. Learning unreal, you want to do quick calculations and fast feedback on any changes of (small) settings.

  2. test and play a lot. For quick testing, I make a copy of the current level and delete everything I don’t need for testing the desired effect. This way, Lightmap calculations are fast and you can test a lot in a short time. Once you’re happy, copy the tested values back into the original level.

This should get you started coming from SketchUp. If you have any trouble feel free to ask.

cheers, Max

Thank you for the great explanation on your sketchup workflow,
a definite must-read. The skp insider tips are great and I use
a similar skp export method for rendering. -Bob

Hi Bob, thanks for the reply. Still learning a lot and trying to improve the workflow.

Here’s two images from a recent project. Not striving for photo realism but just trying to offer my clients a good understanding of the overall design during the early design stages.

To embed the design in its environment I use a panorama of the site as a backdrop (with alpha to show the BP-clouds & sky). For everything but the birds eye view this works fine. It’s just an early concept, the panorama needs some work (alpha of some trees is still bad and there’s too much color difference with the grass-plane.

Talking about grass…thanks to Fighter5347, it was very easy to quickly create a nice atmosphere with his foliage pack. The tree is from Nopal3d’s foliage pack. Really great to be able to use those and not having to create them yourself while still learning Unreal Engine.

I’m a begginer in Unreal, so i don’t understand simply things.
I have big problem with collisions. How to import the interior scene from Sketchup to Unreal properly? After exporting I can’t go into the house, or I can go through the walls or other obiects. How to set up the model in Sketchup to reach the proper collisions effect?
Thanks for help.

I never tried adding collision objects in Sketchup. It just doesn’t fit my workflow. When importing in Unreal, I remove all collision info from each object and only re-apply them for floors and stairs etc. Just search in UE online documents for ‘collision’ and how to apply them.

Glad I found this thread as I’m having issues with SU to UE4.

I tried your method for a simple room, four walls with windows on two walls a ceiling and a floor. I textured the walls and floor in SU and exported as fbx, imported without textures to UE4 and I have light leaks at all the wall corners and where the floor and walls meet. I also am not getting a second set of uv’s auto generated.

My other work flow which also failed was SU to Blender create two sets of uv’s export as fbx then when I try and import to UE4 I get an error message of no triangles found in mesh, when SU triangulates all meshes to begin with.

So, any thoughts would be great!

Thanks in advance…

You will most likely get leaking if there’s overlapping geometry (the floor continues under the wall, or the walls are overlapping instead of a clean cut.
After importing in UE, did you <edit> the objects and change in its <build settings> ‘generate lightmaps’ -> check, <source lightmap index> -> 1, <apply changes>

My workflow for more complex geometry is: Sketchup -> obj -> blender -> add uvs -> fbx -> UE. I’m not sure why you get the error.
Can you share your skp-file? That would speed up resolving your problems quite a bit.

Thanks for the replies in both threads. I had a computer melt down Friday and I am re-installing everything this weekend after that I will do some more tests following your advice. You may be right on overlapping geometry but I won’t be able to test until my PC is back to normal.

Thanks again!

Hi Max! The render looks great, but I was really interested in this topic about the design process. I mean, you have said that you are using UE4 mainly for reviewing options. As I see it, this has been a normal design process that has been “checked” with Unreal. Did you experience any direct change in the design? Something more than simulations/comprobations/reviews?

Hi RodrigoMW,

It’s a normal design process but enhanced with UE. It starts with sketching on paper, just testing ideas. Once I think I have something that could be great, I start modeling simple volumes and spaces in SketchUp - just the key elements. If it still looks promising in SketchUp, I test the design exporting it to UE. In UE I do a low/medium quality lighting calculation and evaluate (walk around) the design. At that point, it’s either refining that design or starting from scratch and adding new designs as new levels to the UE project. That way, you can always go back - or show the client the alternatives if needed.

Light and space are very important to me and UE to me is a tool to test those qualities in a design (SketchUp’s shading capabilities are very limited so there’s no feeling of depth). I don’t think using UE changes the design itself - it’s a tool that helps me evaluating the design myself. Also, it helps communicating the design(s) in the end. Clients really get a good ‘picture’ of what the design is about and how it could look like. Anything that helps my clients making a decision might save time and streamlines the process.


Thanks for your answer Max,
Your design workflow is really direct (I don’t mean I don’t like it). Its a trial error experience in a kind of 3 stage process. Starting with sketches to the main purge in sketchup, to UE4 to the final check. But somehow, I expect something more.
Maybe using using VR to map data during an “analysis phase”, phisics simulations, emergency plans… sunlight studies…etc… In this video: Virtual Reality in Architecture Design & Review - YouTube The VR researcher is talking about asking users who don’t know the design, to explore the space in VR to analyse how people react. Archviz is only the first step, and your approach is (for me) the second. But I believe we are in the VR paleolythic, even more in architecture!

Im about to buy a new PC able to handle UE4 (nope with my actual laptop :frowning: ) but Im just looking forward to make 1000 experiments. Keep in touch!

Hi RodrigoMW,

The video and your ideas sound interesting. I expect you need more larger scale projects for ‘something more’. I only do (small) housing and remodeling projects.
Still, curious to see what kind of possibilities lie ahead…


Hey Max,

First off wanted to thank you for the step by step explanation of the pipeline.

I’m having difficulty creating clean meshes inside SU. We are trying to work directly with Architectural firms so we will be dealing with a lot of blueprints, which is why I want to integrate SU into my workflow.
My problem is that when my model gets too complex, I find that the geometry is broken bad. The way I found this out is when I import the model into UE4 I always get collission and overlapping errors. Funny thing is when I imported it into my main 3D too (C4D) it looked fine but since UE4 gave me errors I figured I’d redo the mesh using Zbrush’s Zremesher too. When I imported it into Zbrush the geometry looked terrible, which I imagine is what UE4 noticed when I brought it in.

I made sure to group this element, which is a single mesh roof, and exported it as a separate fbx. Are there any resources as to building optimized and clean models into SU, without needing a 2nd party program, or do I have to take it into some other program?

I’m looking forward to seeing the end result for your project.


Hi Artun,

I’m not exactly sure what you are trying to say by ‘broken bad’ & ‘collision & overlapping errors’. You mean z-fighting? Faces that are (almost) exactly at the same position and causing the z-fighting effect? Maybe you could share a picture illustrating your problem?

When modelling in SU I try to follow a few guidelines. It’s a workflow that suits me because I make 3d models in SU for creating construction documents in Layout afterwards. It turned out, models made like this suit UE as well.

  • use solids as much as possible -> Every building material (or almost any object around you) is a solid volume. If you model everything as a solid object, the objects tend to be very clean. Clean objects are more easy to deal with in SU and cause less artifacts in UE.
  • solids ‘never’ intersect -> if they do, one part will be hidden from lighting and shadow bleeding / artifacts can occur (or you need HQ settings in UE to fix that). Also, if they intersect in the same plane, z-fighting will occur. Sometimes, when exporting to UE, I do add a few cutlines to objects (intersections for beams in walls for instance) to prevent shadow bleeding.
  • use as less faces as possible -> by doing so, the objects won’t slow down SU as much and will keep your calculation times in UE fast. For instance, if your scene looks good with a single textured volume (plane) for the rooftiles, it would be insane to create a high poly model for these rooftiles. That would slow down SU and UE a lot.
  • test from the beginning and test a lot → the feedback will prevent errors, increase quality and prevent wasting time

A lot of people don’t like solids and have a totally different workflow. Just try out different techniques and choose whatever fits you best.

Cheers, Max