Hello everyone,
I’m part of a small amateur team, and I’m investigating the possibility of switching to UE4 from Unity for our project. I’m not here to start an engine debate, I just want to get some answers if I can, about particular UE4 features from people who worked with them. I’m asking so I can estimate whether it is worth the hassle to migrate our project to UE or stay with Unity.
I’d like to ask someone who worked with UE4 terrain system how well is it done? Are there any known problems, quirks? Words of wisdom? Here are some key points that are important to us:
Does UE do terrain LODS/tesselation/clipmapping out of the box? Unity terrains have a built-in system where farther parts of a large terrain are rendered with less tris.
Can bumpmaps/specular maps be used with terrains? Can custom shaders be plugged into terrain rendering?
How well does UE handle terrains performace-wise? I’m not sure how exactly Unity handles terrains, but in our performance testing we were able to load 4 times the amount of terrain we would ever use and experience no notable detrement to performance on our target system. It is important for our project to handle vast amounts of space graciously.
Can heightmaps be used to build terrain? If yes, what format heightmaps does UE eat? Unity only accepts a proprietary Photoshop .raw format that is a pain in the hind to work with.
How good are terrain sculpting tools? In Unity they leave much to be desired. We found them useless there, maybe UE has it figured out better?
How graciously do large terrains handle realtime dynamic lighting/shadow casting? This is the main reason why we are not happy with our current project state. We are doing day/night cycles and Unitys’ terrain shadows are usually destinctly lower in resolution, jagged and sometimes there are shading artefacts in the distance. Point light at night is the biggest culprit, producing really blocky shadows.
World streaming? Unity doesn’t offer world streaming as a feature, so we divide our world into chunks of 1000x1000 units and load them ahead of vision range. If UE offers streaming terrain from a file maybe we can explore that option.
Does UE handle collisions with terrain, or will we have to write it ourselves? In Unity you don’t need to do much about it since it’s handled well by the engine itself.
Is there realtime terrain modification support? This one is more of a bonus feature, but it would be nice.
Anything else you wish to share regarding your experience with UE terrain system is welcome.
Thank you for your time, hopefully I don’t get massively ignored.
Yes, pretty much anything that you could throw at a regular material, you can throw at a terrain material. There are a few small exceptions, but not many.
They work pretty well depending on the terrain resolution, material layer count and complexity of the material.
Yes, you can import 16bit heightmaps for the terrain and you can use 8 bit raws and pngs for layer blending with things like splat maps.
They are pretty decent, but you’ll have to play with them a bunch to really learn the ins/outs of it all.
Very well. You can have cascaded shadow mapping, distance field ambient occlusion, distance field shadows and so on. It’s all up to how you tweak your parameters and settings.
Yes, UE has streaming and it has a tool called world composition for handling really large worlds with many tiles to them.
Yes, it’s automatic.
I’m not sure about this, but I’d assume not right out of the box.
I have entered the unexplored waters of UE. I’ve encountered the superb material editor, I’ve encountered the nice editor tools, but most of all I… encountered strange lines that go through all of the terrain. Can anyone tell me what this may be caused by? The material is nothing but a constant colour. Light source is a movable direction. I think it may be something with my imported height map image that rubs the engine the wrong way, because if I modify it in the engine, the modified parts don’t exhibit this.
You can adjust that with the shadow bias setting–it happens when the angle of the light is close to the angle of the surface, it also affects how close a shadow will line up to an object that casts the shadow (like if an object is on the ground it may look like it is floating)
Yeah, you probably need to build lighting to remove the lines. Removing static lighting everywhere is probably a bit overkill, maybe you want some things that use lightmaps even if you don’t use them for the landscape.
