Mirrored Light Objects

[Chris_RSI]

Hi,

If I have a mesh set to emit light using black body emission, and I mirror the object, the light stops emitting on the mirrored object.

Is there a fix for this?

Thanks.

[profbetis]

This may be caused by flipped normals

[paride4331]

Hi Chris_RSI,
I think you have a problem with mesh normal.
I hope the following links can help you.

Viewing and Changing Normals

Regards
Paride

[Chris_RSI]

I thought that too, however if I flip the normals of the mirrored part it has no effect. If I mirror the part back again the light functions normally.

[paride4331]

Hi Chris_RSI,
the basic rule is that the light emitting is always on the side of normal.
Without some detail , for example a screenshoot, it is difficult to better understand your problem specifically.
Regards
Paride

[Chris_RSI]

It's pretty easy to reproduce.

Create a sphere, apply a self illuminating texture using black body emission. Render on a flat plane so you can see the light spill out onto the plane.

Mirror the sphere, and the light stops emitting. Sphere normals are correct and the sphere shows illuminated.

Try flipping normal and the light emits, but now the sphere normals are reversed and the sphere is not illuminated.

[paride4331]

Hi Chris_RSI,
I tried to mirror the ball around all axes with no problem.
Are you sure that you refer about mirror command ( tolls > mirror) ?
Regards
Paride

[Chris_RSI]

I am sure that the mirror tool is the tool I am referring to. I have attached the max file for reference, with the sphere already mirrored (same as the last screenshot I posted).

This leads me to wonder if it is a version issue, I am using Max 2016, SP3, Ext2, and Octane 2.25.

It might be time for me to bring everything up to date.

light test 1.zip

(43.87 KiB) Downloaded 194 times

[paride4331]

Hi, Chris_RSI,
I tested your shared files with 3ds max 2016 and octane plugin 2.25 - 2.22 and it seems to work fine.
Your sphere has some kind of problem indeed, so I tried to make a mirror copy, removed the modifiers you added and it works fine as well.
I have also tried to create another sphere, mirror it and it works fine as well too ..
I attach your file with my changes, try to take a look.
I do not think Octane 02.25 is your problem, but consider Octane v.3 can still be a good idea!
Regards
Paride

[Chris_RSI]

Hi paride4331, thank you for taking the time to take a look, I must sound like a crazy person when I'm the only one experiencing this issue

This is really strange, I am noticing some odd behavior in the file you uploaded.

The first thing I noticed is that in the Octane render viewport, if I move my sphere around I have to refresh the Octane viewport to see it move. However if I move the spheres you created the Octane viewport shows them moving in real time, without having to update the window.


If I just simply mirror my original sphere, I get the same effect as I did before.

If I mirror your spheres, they work just fine, and in fact update live in the Octane window. If I make a copy or instance of your sphere while mirroring it works just fine, and updates live in the Octane window.

I would love to know why the spheres you created are updating live in the Octane window, and are functioning correctly. Every sphere I create has the same problem when mirrored, it is a little frustrating.

I'm going to upgrade max on Friday to 2017, maybe there is something wrong with my install of max?