Wrong shadows

Why shadows are curvy on straight cube object ? There is 3 different objects. White is Ue4’s cube.Other’s Uvs are scaled to low. Other is standart Uv directly exported. So as i understand uvs are not affects on shadows. The main question :Why shadows are curvy on straight cube object ?


If this is static lighting it’s highly possible that the receiver surface has a low lightmap resolution!
…if not: you’ll have to share more information about your scene!

True,but can’t we set lighmap resolution automatically ? By manuel i can’t get the correct number. 256 is too high. 4 is too low+wrong shadings. I don’t know what to do.

??? I’m not sure if I fully unserstand you… :S
What do you mean by automatic lightmap resolution? Like Unreal would read your mind what quality you want and set the correct lightmap resolution according to it? :wink:
It’s in YOUR control!! Of course in the beginning Unreal will set a “random” lightmap resolution to the meshes… if you like you keep, if not you change setting as in any other software…
…there are also numbers between 4 and 256…

Hmm.Alright. Can i ask a last question? Should i give numbers like 5 7 13 19 27 ? Or i should give numbers as 4 8 16 32 64 128 256

You can ask as many questions as you like!! :slight_smile: We’ll try to answer them! :wink:
I personally would stick with those even numbers! …I’ve seen who doesn’t!!
…I think I’ve read somewhere (I might be wrong!!) that if you use in-between numbers it will round up anyway to the closest higher one, so you’ll just waste uv space…


Hey, I think i solved my problem but im not sure.I setted cascated shadow maps and got much more better result.But does it has any bad sides ? Im getting a good render even if i setted their lighmap res. 4 .

Cascaded shadow maps are like dynamic shadows so will be the best quality, they don’t depend on any lightmap resolution!! You’ll have a shadow change/shift by distance usually… I think it’s as expensive as a dynamic light: the most, since it’s calculated realtime…

If i set to movable, im getting good shadows too.So what is the difference ?

Oh Wait ! I solved my problem !!! I got it ! Thank you for your help

Dynamic lights won’t produce GI!! …and they are the most expensive lights on runtime: they have to be calculated realtime! Baked lighting information is the chepest: they are pre-calculated maps!

Dynamic lights can produce GI via post process, and/or ray tracing. OP, I was getting the same shadow problems with meshes in a template level by UE. I wasn’t sure how to get rid of those either. So, I checked a number of things, and was able to somehow get rid of it without changing to dynamic only lighting. Try these:

Lightmass Importance Volume - its bounds (the bounding box) have to be around all shadow-casting objects, so not on their edges or intersecting at all with the objects or their shadows. So for the cubes, ensure that the volume, if it’s in the level, has its bounds surrounding all the cubes, their shadows, and that its invisible sides (have to discern by the box outline) are not too close to the edges of the objects / their shadows, and definitely aren’t intersecting them. To change its settings in post process, select the Post Process Volume in the World Outliner, go to Rendering Features > Light Propagation Volume, and enable any settings that you intend to change. Any that are unchecked are not going to get results at all, they are disabled.

Skylight - If not showing what’s below the horizon (lower hemisphere) of the level / terrain, go to Lighting part of Skylight’s details panel, then set Lower Hemisphere is Solid Color to unchecked. When its checked, it is causing bounced light (indirect) to get re-projected back to the skylight and then mapped to the level. This causes odd lighting information to get cast on the objects and can create shadow lines on surfaces, wavy shadow edges, and other artifacts (like coloration of the light when it is checked and a color is chosen). And after changing Skylight’s settings, click Recapture button in its details panel before Building lighting and for viewing the results.

Directional Light - First, only use one until you know how to work with this type of light more. Second, there’s a setting called Shadow Filter Sharpen under the Light part of its details panel. To access it, click a dropdown arrow to expand the list of settings under Light. It’s under Shadow Slope Bias. Increase it a little bit at a time to see if it corrects / enhances the quality of the shadows. Also, above that in Light settings, uncheck Atmosphere / Fog sun light. This may get rid of the curvy shadows, and if it doesn’t, then it could be in conjunction with another lighting object (the Atmospheric Fog actor). If there isn’t an Atmospheric Fog actor in the level, then leave it unchecked. Otherwise, it could be tweaked in conjunction with the directional light’s Atmosphere / Fog sun light setting being enabled.

If using stationary lights at all, then remember to build lighting after changing things. Building the level, and not lighting only, can also potentially solve problems.

Power of 10, dont be afraid of 2048/1024 on objects that need such immense resolution.