UE4 refraction problem and depth fade problem and....well.. water ;)

aphexx

hello,
i have some problems with my unreal 4 water...
it's also a thread in the answerhub on the unreal site, but perhaps you can also help me out.

here are the key problems...well basically these are all the problems you can probably have with water haha :

1. Reflection:
since i didn't manage to get reflections with translucent material types, i used a rendertarget which is not too accurate, but works somehow. Is there a way to make translucent materials reflect without render target?

2. Refraction:
i get visual artifacts with refractions, the whole under water surface displaces too much against crossing geometry.
however, i do not need real "glass-like" refraction, i only need a distortion effect based on the normal maps, that make the small waves on the surface. how will i create a distortion effect instead of a full blown refraction?
since i do not know what i'm doing, i tried to use an inverted fresnel in the refraction slot to get rid of the most obvious artifacts.

3. Depth:
i think i didn't get the concept of depthfade vs. refraction. when i use greater values in the depthfade-fade distance than ~250 i get some water depth effect, but also heavy refraction issues around the geometry that is inside the water and when i use a pixeldepth node it won't work also.. how would i use the depth fade with refration?

(never mind the assets, they will be replaced haha)





here is a small video, showing the artifacts in motion

[ame]http://www.youtube.com/watch?v=RsSdgtlE5Nw[/ame]

LMP

Unfortunately, I don't think even Epic has a good answer to these problems yet... they talked about it in one of their live streams recently.

aphexx

hmm too bad. thank you, i think i'll watch the stream eventually.

JordanW

1. reflection, use surface lighting type for translucency and it should get reflections from sphere reflection actor.

2. refraction should be 1 = no refraction and you go above or below to change refraction index. its scalar so you don't need a normal map, or you could use like blue channel or something. I also like to tone down refraction the depth fade so it doesnt cause a seam at intersection.
3. So you would use depthfade plugged into an alpha of a lerp, and it would blend between your desired refraction amount and 1

aphexx

cool, thank you for the fast reply!
i tried it out, but i cannot get it to work. i believe i forget something.

the reflections won't show up. sphere reflections are placed but the water in my indoor scene won't reflect. though it is set to surface lighting type.
i removed the diffuse component that is shown above. i was also told to set a high specular value when using surface lighting, but that also won't work.

the refraction is also totally messed up with heavy seams, if i put the construct you told above into the refraction slot. think i just do not fully get it.

but thanks for your reply anyway, i'll try some more!

hmnyari

do you solve this problem??
I have same issue...
I can't fix this. please help me.
https://answers.unrealengine.com/questions/375188/water-shader-tutorial-refraction-issue.html