How can I get emissives to glow through a translucent?

TheAxiom

UE3 question here.

Basically I have two meshes/maps here. The light with the bulb and the glass. The light has an emissive on it to make the bulb glow but the glass, which has translucent on it is blocking it.

Simply put, how do I get the lightbulb to glow through the glass?



The other lights in my environment work how I want them to

repete

Try this on your glass material:

disable "Enable Separate Translucency"

change the "Translucency Lighting Mode" to TLM_Surface

TheAxiom

"Enable Separate Translucency" was disabled by default, but I have no clue how to change it to TLM_Surface. Is that not just a UDK4 thing? I've looked everywhere and nothing on Google for UDK.

Obscura

Isn't that under the "lighting mode"?

repete

Forgot your on UDk

Try this frist: MLM_Phong or MLM_Custom and set the Blend Mode to Blend_Translucent.

Long time since I used UDK so you might what to look into the lightmass settings.

https://udn.epicgames.com/Three/Lightmass.html [Mesh Area Lights from Emissive]

What your trying to do should work.

TheAxiom

Yeah I did read through that before but didn't see anything that helped. It was already on MLM_Phong with Translucent, the custom didn't change anything except made the glass black. Tried inverting it and messing with the opacity but still no glow coming through.

I might just have to make the glass glow it's self. I couldn't get it to look good earlier but I can keep trying.

repete

You did try using "Use emissive for static lighting" under the static mesh settings and also adjust the "emissive light explicit influence Radius"

TheAxiom

Yeah I have. Doesn't that just create light from an emissive map? So it would just mean I wouldn't need a spotlight or something there if I gave the glass an emissive. My problem is the alpha blocking the glow. I guess the bloom glow works like an alpha and you can't have them overlapping can you?

I have a fog alpha texture infront of my alpha windows and they don't work together at all. If you turn your head the fog is off, then turn your head the other way and it's on.

repete

This the best your going to get:

www.youtube.com/watch?v=3WY87JqUFEg

TheAxiom

Yeah that doesn't seem to change the bloom effect, that only creates light.

repete

Just a shot in the dark here, have you set your translucent mat to TwoSided ?

repete

If this is doable then what's the difference to what your trying to do !!!

TheAxiom

It's still different. That's light being created by the emissive, I don't care about that. I want the bloom's GLOW effect that is on the bulb behind the translucent glass to glow THROUGH the glass. I don't know how else to explain it, sorry.

radiancef0rge

Im pretty sure this is not possible. As the glass is rendered on top of the pixels that would be blooming - and are no longer reaching the > 1 threshold.

you could try making a glow mesh that encapsulates the mesh or use a flare

Der Hollander

It seems like you could either ditch the bulb or ditch the glass for such a small asset, and get a result that would work for you.

Personally I would just ditch the bulb since it's so small anyway, and then fake the bulb by adding an emissive colour over an opaque glass texture and masking it using a DotProduct multiplied over the emissive value. You'll save yourself some extra R&D time and also save on unnecessary draw calls for something that's gonna be like, 10 pixels on screen.

If you're utterly hell-bent on keeping the mesh as-is, you could try inverting the normals of the glass, set it to single-sided shading so you could get glass reflections around the side and back of the object, but not the front and the emissive glow should theoretically show up.