LuxCoreRender Forums

Hello. How to create such a translucent material (a sheet of paper) with some image texture? In the photo I'm directing the sheet towards a lamp and able to read what is printed on another side. Is it possible to do this with LuxCoreRender in Blender?

You will have to give the mesh a thickness (e.g. solidify modifier) and assign two different materials on both sides.
Make both materials matte translucent, but give them different diffuse and transmission textures.

Here's an example scene.

I've tried to do this with the same texture as in the photo and it doesn't seem to work properly. I've get some weird inverted shading. Symbols appear lighter than the rest of the sheet. What might cause this?

we need a doublesided material for this. It is not currently possible using shaders in luxcore imho.

Did you plug the texture in both reflection and transmission color?

B.Y.O.B. wrote: Sat Feb 16, 2019 12:20 pm Did you plug the texture in both reflection and transmission color?

Yep. I attached that .blend with the texture in the previous post.

the problem is that your texture is completely white (1), while my texture is grey in the bright parts.
This means your texture reflects ALL the light in the bright parts, so nothing can be transmitted. But in the darker parts (the text), not everything is reflected, so some light can shine through, creating the "inverted" effect.

The solution is to set the brightness of the imagemap to something lower, I used 0.7 below.
I also disabled the fill light to make everything more clear and made the mesh a bit thinner by scaling it.

Thanks for your help and good explanation

I added a little bit of emission. This is a hack, but there seems to be a lack of transmitted luminosity without that. Could there be a physically based way to do this?