The first thing to consider in the pipeline is preparing the asset for game engine interactivity. Architectural models/meshes can have very high polygon counts as Arch-Viz up until recently has relied on ray-tracing renderers like V-Ray or mental ray. Poly count isn't really an issue when rendering out beautiful 8K stills on a render farm, but for real-time interactivity it is vital to keep meshes as low-poly as possible. Good texturing and utility maps can be used to bring out details.
I am using Maya as my 3D content creation application. For testing purposes, I have used an old Nordic cottage that I modelled a few years ago. The roof tiles are all separate meshes, which explains the high poly count. To get the tile details into Unreal, a normal map will need to be baked on to a low poly shell that outlines the main shape of the roof.
The original exterior walls were made up of timber panels running vertically along the perimeter of the model. I deleted these and remodelled the wall geometry maintaining the original ope positions.
The next step is to break up the asset into separate meshes that can be imported into Unreal separately. For example, the wall geometry can be combined and exported as an fbx, then the roof geometry, door, window and so on. It is better to do it this way rather than exporting everything as one fbx file for workflow efficiency. The world space locations will be saved in the file so there is no need to re position everything in Unreal. Although, instances of the window asset will have to be placed in each ope.
Before I move into Unreal, the next step is to clean up the UVs and bake utility maps from the high poly meshes...
Polygon Count Reduction
I am using Maya as my 3D content creation application. For testing purposes, I have used an old Nordic cottage that I modelled a few years ago. The roof tiles are all separate meshes, which explains the high poly count. To get the tile details into Unreal, a normal map will need to be baked on to a low poly shell that outlines the main shape of the roof.
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| High Poly version of cottage asset - 600K + polygons |
For the window meshes, as they are all identical just one needs to be prepared which can then be imported into Unreal and instanced. There are a lot of superfluous edges on the geometry that can be deleted. Holding edges will remain in tact to maintain the shape of the asset.
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| High Poly window asset - Ambient Occlusion and Normal maps can be used to bring out the details in the shutters and frame |
The original exterior walls were made up of timber panels running vertically along the perimeter of the model. I deleted these and remodelled the wall geometry maintaining the original ope positions.
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| Main walls - holding edges are still needed around the door and wall opes and to maintain the shape of the gables |
I continued this process of reducing the poly count for all meshes on the asset including the front door, gutters, gable frames, etc. It is important to maintain the main shape of the original mesh so the original details can be baked onto the low poly versions. I managed to reduce the poly count to just over 30K. With more time this could have been reduced further, but for a big asset like this, 30K polygons is not too bad.
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| Completed low poly asset - Poly count is now 30K |
The next step is to break up the asset into separate meshes that can be imported into Unreal separately. For example, the wall geometry can be combined and exported as an fbx, then the roof geometry, door, window and so on. It is better to do it this way rather than exporting everything as one fbx file for workflow efficiency. The world space locations will be saved in the file so there is no need to re position everything in Unreal. Although, instances of the window asset will have to be placed in each ope.
Before I move into Unreal, the next step is to clean up the UVs and bake utility maps from the high poly meshes...
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