If I try to set the size of a RenderTarget2D to something higher than 2048 it get’s reset to 2048. Why? Is there any way to create a RenderTarget2D with 4K or 8K resolution? I don’t need to update it every frame, so I don’t care much about performance.
Without modifying the source, no 
Why do you need such large resolution for a render target?
I’d also like this.
I need a high resolution capture of a landscape in an open world, rendered from a top-down camera. because of reasons (in-editor procedural generation of flow maps)
I also won’t update it every frame (in fact I will only update it at editor time)
Hey guys, added UE-13387 to investigate. I see no reason why not, as the RHI max is 16k 
Thanks! I would really like to see this increased in 4.8.
Doesn’t Unreal4 have something similar to the “skybox” in Source engine? where it just renders out a native resolution of another location in the “skybox” level wherever the player is looking.
Any update on this? If it would be only one number to change I would like to see it in 4.8
The scene render targets including GBuffers have to be allocated to whatever size the scene capture is. We found in the past that making these huge (>2048) tanked performance as there would be nearly a Gigabyte of render targets, which most GPU’s cannot handle. Ideally this value would be exposed on the scene capture for you to bypass, but we haven’t gotten to that yet.
Thanks for the answer !
So you say that one single RenderTarget2D with a resolution of >2048 would take almost a gigabyte of VRAM, even if it’s only created once when the game starts and after it never updates? Why does it take more memory than a texture with the same size? Can’t you store a RenderTarget2D in a nice small compressed way? 
Long story - it has to do with the way the engine deals with shading and geometry - deferred shading. In order to render and light a 2048 scene capture, the GBuffers have to be 2048 as well, and they are huge.
Any news on this. 2048 x 1024 is a pretty small cubemap
Up to 8k is allowed since 4.13.
I still can’t set my cube render target size to more than 2048 on the X axis, how to get 8k?
It seems to be still limited to 2048, right? If I try to put a higher number, it gets campled to that maximum.
Are you sure, you use the correct render target? Because there is the Cube Render Target, which is still capped to 2048, and then there is the normal 2D “Render Target”. And the normal 2D Rendertarget can go up to 8k for each side. The Cube render target is still limited to 2k
Render Target (2d):
For cube render target, see this:
Thank you @Suthriel ! Certainly I was talking about the Cube one, but because I thought they were talking about it here, insted of 2D. My fault, sorry!
But thanks again, also for the link.
Best regards!