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.
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).
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).
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.
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)
- 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.
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>
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.
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.
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.