Hey guys here is a simple one that I keep seeing mixed emotions on…
Is it better to have a large texture (4096 or 8194) and use one mesh to do a house for example, or to do 4 to 5 smaller meshes, each having smaller textures? I know you can create material instances and basically make it free but then you also have a lot more lighmaps to render.
I am building houses that are around 900x900 units by 250 tall (Single Story) and I am using up to 5 meshes to make up the body of the house. I have individual meshes for each room, the main inside living area, and the exterior. Each color is a different mesh (minus the two green rooms, they are separate meshes, just the same color) and I have broken them down so the texture still look good on the walls and not blurry. Many of the rooms are reused throughout the game with many other house designs to keep the number of meshes needed to a minimum. I just rearrange the inside rooms and build a new interior and exterior for the new house.
See example:
It is not only a matter of texture resolutions, but also of draw calls. If you have the entire housee as on emesh, you will always have a draw call for the whole house, no matter where you are looking at. Also you would need a really high lightmap resolution to capure enough details.
In your example, I would even split the pink part into smaller sections.
Give the walls some thickness and make them modular. Walls, window awnings, etc.
For the window sections, you could even choose a 1024 texture…
The only advantage of having it in one mesh is that the shading for all parts would be dertived from the same irradiance cache and thus be shaded continously…
In my last building I split the exterior into two meshes and was able to apply the same 4096 texture to them both and the end result was very nice. I am trying to keep my resource cost to a minimum whether it is texture resolution, draw call amounts, lightmap sizes, and also the large amount of time I have making the textures.
The issues in the thread you linked came from the differently shaded meshes being coplanar. This makes it very obvious.
So, if you make the splits only at corners, it will be completely unnoticable.
A good example in your screenshot above would be the window elements.
If you make the wall a bit recessed, the shading would look natural, even if shaded slightly different than the rest of the wall.
Also it would break up the wall a bit and make it moreinteresting. Actuially most windows in real life are a bit recessed as usually a radiator is fitted underneath which is not supposed to stick out into the room… (At least where I live :p)
In pure direct light, you also can get away with coplanar meshes as the shading difference only arises from indirect lighting.
I recently made a little testmap whare I mostly use modular design. https://forums.unrealengine.com/showthread.php?73637-A-little-FPS-level
As you can see, there are also still some shading differences. But I will eliminate them one by one
I actually have a separate mesh to add where the window holes are that are recessed as you said and consists of the frame and glass. I fill them in after it is all imported to UE4. I am going to do some tests myself and check out render time, memory usage and fps with a couple different options. I am still learning the best techniques to used for mesh building… I am old school and would rather build everything out of bsp’s but even after you convert them to a static mesh you have to create a valuable lightmap for them because they don’t look good by default. I mapped with hammer editor with the source engine for years and it was much faster to build levels. I wish the bsp’s would get optimized better. As soon as you map downloads I will take a look.
