LuxCoreRender Forums

I'm fairly new to Blender and Luxcore so have a lot to learn so apologies if this is a really daft question. I'm trying to get the light rays reflected from the gem to cast shadows via the text that's in front of the gem - making the text more legible. I'm not sure why this isn't happening already, can anyone advise?

Image: https://drive.google.com/file/d/1pNYR54 ... Q_qpA/view

Blender file: https://drive.google.com/file/d/1AVI_56 ... sp=sharing

From quick glance, your letters have "Null" surface & HG volume, but are flat.
Giving those objects thickness, makes them render "correctly" - transparent.
Then, you have Volumes inside Volume, and to render those w/o issues, they need to have priorities defined along with In- & Ex-terior Volumes, World & Camera Volumes (Last two are automated, but still...).

Do note:
LuxCore is physically based rendering engine, meanining it's based on "standard model of physics". It doesn't render shadows casting from invisible object. Transparent (Null surfaced) object only casts shadow when its medium (Volume) is dense enough. And there's no "mechanism" implemented to fake it (like Corona's "Ray switcher".)
So, if you haven't yet, check LuxCore tutorials @ YT & Documentation.

BTW, what is your goal, any visual reference to show?

Thanks for the advice, that really helped. I removed the null material, extruded the title and added a glass material - it's definitley more what I'm after now, the light rays from the ge are interacting with the text which is what I wanted all along.

Great, glad you found it helpful.

And about "invisible object casting shadow", uncheck "Visible to Camera"in "Properties Editor / Object Properties".
It totally slipped my mind.