Translucent material shading problem

anonymous_user_8ef146d21 · March 17, 2015, 11:45am

Hello everybody!
I have a bit of a problem with a translucent material. Is there a way to make a translucent material with 1.0 translucency properly lit?

Here’s my current translucent material:

And here’s a material I would like it to look like.

I still need the translucency for fading the material(with a changing parameter). Is it possible to do this with a translucent material or do I have to use a masked material with a changing parameter( I haven’t gotten it to work though)?

anonymous_user_8ef146d21 · March 17, 2015, 8:15pm

I changed the translucency lighting mode to make it a bit better but it still isn’t a full fix.

Haflurgaflur · March 22, 2015, 5:46am

Try changing the blend mode to masked, and the Shading Model to Subsurface. Then give the opacity a value of 1 (or 1.1 to make sure its 100% not translucent)

A thing to take note of is that even in translucent shading, when the opacity value is set to 1, it is still slightly translucent. This is because a translucent object in the real world can not be opaque.

To do the “Fading” effect there are two ways:

This is a cheap looking, but really easy to understand. First create a simple Gaussian of your desired blur For example:

Then plug it into the opacity mask (and/or Opacity, it changes the effect slightly)

This one is a little odd, but works, First open up your material,
then add a Fresnal under the Utility. Plug the Gaussian into the ExponentIn. Then plug the whole thing into the alpha of a Lerp. Plug your favored Scaler Params into A and B. Then plug the Lerp Output, into the opacity.

Now for the Colors. Plug two colors into a lerp (A and B). Then plug the Fresnal Output into the Alpha. Then finish off and plug them into The base color.

Here is an example of #1

Here is an example of #2

And Here is an example of Both on a tiled plane

anonymous_user_8ef146d21 · March 23, 2015, 10:50am

Thanks for answering! Actually by fading i meant fading the object invisible over time. And i have gotten this to work with the translucent dynamic material by controlling the opacity parameter in blueprints with a timeline that takes it from 1 to 0 over time. However i do experience the lighting issue. And i tried doing almost the same thing with a masked texture by lerping but it seems to only render it fully invisible or fully opaque(by changing the alpha). So do you happen to know anything about that?

Haflurgaflur · March 24, 2015, 5:44am

Try Playing with the Translucency Lighting settings. (If you haven’t already…)
Then adjust the Spec and Rough areas along with your opacity.

This probably won’t help, but I usually add a subtle normal map, and multiply (By use of a TexCoord) it by…like…12…

anonymous_user_8ef146d21 · March 24, 2015, 8:10pm

Playing with the settings doesn’t seem to do much but i guess it really isn’t possible to get it shaded exactly like the opaque material:P thanks!

anonymous_user_5679c567 · April 11, 2015, 12:22am

You need per-pixel lit translucency, which is currently a super super alpha feature that doesn’t support a lot of stuff and is really buggy. I last found it in Epic’s latest build around late February (it still exists, but I don’t know which build it’s in now). If you were to grab their latest build off github, you’d find it in the material editor under TRANSLUCENCY. The dropdown menu (which in 4.7 has the TLM Volumetric Non Directional/TLM Volumetric Directional/ TLM Surface) would have this like per pixel lighting selection.

It’s what you need, but I think you’ll be sorely disappointed with it.

anonymous_user_8ef146d21 · April 13, 2015, 7:37pm

Okay thanks! I guess ill just have to wait for that then:P