Lighting problem (Flame 2024.2)

Hi all,

it’s been a while since i used the lighting in Action, but the normals don’t seem to behave as i expect? I have a single layer (white frame) with a light illuminating the front. If I add an axis to both & rotate them round to look at the back, it’s also illuminated?

i’ve made a jpeg here showing the setup, with views from a front camera & a back camera, both outputs are lit;

it’s almost as if ‘Force 2-sided’ is permanently on, even though it’s not? Maybe I’m missing something, just wanted to see if anyone has any thoughts before i log with Autodesk?


Hmm. If toggling 2-sided doesn’t fix it, you could try this: add another white frame behind the front white frame, offset by one pixel in Z. Light-link a Shader set to “Shading off” on the back surface only. Try that?

*and make sure Z-buffer is on in Action rendering prefs.

1 Like

Ye I guess that’s a workaround for it, thanks GPM.
I’m creating a flock of butterflies with a body geo & lots of varied 2D wings, just annoyed I can’t light them properly. Have tried it on Linux & MacStudio flame & it just doesn’t work.

What kind of shading type are you using? Physical? I can’t think of any time I’ve seen this…

At the moment it’s just straight up geo & image surfaces with default shading & 1 lamp. Dunno if anyone else can replicate in 2024.2 but it seems like a bug.

One other thing to try (and I’m not at the box) — if your geo can split our into front/back/extrusion groups (there should be a toggle in the geo), then try adding a shader that is light linked to just the back, set to Shading Off, or messing with the Material node settings for just the Back group. That would save you from having to duplicate geo, which would start to add up with a bunch of fine feathers.

I’m pretty sure this has always been the default behaviour with images. If you want self shadowing then you need to use geo.

If you need a wing shape then use a 3D shape with a gmask

Cheers Leo. I guess i just forgot how bad the lighting was!

I actually did this very same thing a couple of years ago. I had to build 3x moths that were flying around 3x lightbulbs. They were sillhouetted by the lightbulbs. I used a simple cylinder geometry for the body that I projected a still of a moth body onto, and I ltierally cut out each wing and animated it as a plane. The lighting in action worked a treat and I didn’t have the issues you had. I also had the wings interacting with the light so there was some nice occlusion and light flicker when the moth was between the lightbulb and camera.

I will see if I can find a link to what I did. Unfortunately I can’t share the setup as it was at a previous company,

1 Like

This is the series and it is literally the opening shot of episode 1
Bad Behaviour (TV Mini Series 2023) - IMDb
Unfortunately it is on an Australian only streaming service and I don’t have access to the shot or setup.

Actually, when I come to think of it, I did want the lighting interacting with the background to get the lightbulb flickering properly and shading the light cast by the bulb. I may have even graded down the shot light so my added light worked. However, at an early stage I had my 3x Action lights linked to the moth setups so they didn’t affect the background before realising that I actually did want to for the reasons mentioned above.