negative object, flipped normals

Dune · September 15, 2019, 04:55:13 AM

There's something I don't understand (may be an early morning issue); sometimes I want an object to be mirrored, so I negate the X or Z. Consequently, normals should be flipped, but it seems that is not always the case. Yesterday I rendered something that way, but the object was 'negative' (dark, with light on the wrong side), so I undid the flipped normals, while the Z was still a minus 1. Rendered again and it was okay. Mmmm.
This morning I did a little test. This time, as expected, with the Z=-1 and flipped normals it rendered good, but didn't with non-flipped normals (and Z=-1). Either in normal render mode, defer mode or PT. The RTP however looked okay, whatever I changed, thus contradicting the final render.

bobbystahr · September 16, 2019, 10:05:38 AM

hmmm, following this.

Dune · September 16, 2019, 10:24:18 AM

Yeah, me too

Hannes · September 16, 2019, 10:58:06 AM

Quote from: Dune on September 15, 2019, 04:55:13 AMYesterday I rendered something that way, but the object was 'negative' (dark, with light on the wrong side), so I undid the flipped normals, while the Z was still a minus 1. Rendered again and it was okay. Mmmm.
This morning I did a little test. This time, as expected, with the Z=-1 and flipped normals it rendered good, but didn't with non-flipped normals (and Z=-1). Either in normal render mode, defer mode or PT.

Are you talking about the same object behaving differently the other day, or was it another object?

Dune · September 16, 2019, 11:33:24 AM

It was another object, but I can't see why that would matter. I can test with that object too.

Dune · September 16, 2019, 11:41:20 AM

And here are the results from the Netherlands!!!

So, what happened on the other computer.... maybe I didn't look too good. But the RTP still shows it wrongly, as it will be rendered differently than previewed (if settings are not right, that is).

Hannes · September 16, 2019, 12:05:06 PM

Bizarre!

sjefen · September 16, 2019, 01:45:08 PM

Can I just ask why transform scale = -1 tho?

- Terje

Dune · September 17, 2019, 01:45:24 AM

To flip an object, so the right arm is left. I was not satisfied with the shadows across some kid and flipped him, so he looked better. It's also handy to do when you have a flock of grazing sheep; one object, two pops, but different looking.
Strangely; a large render just finished on another machine, where the boy was flipped over X, but normals weren't flipped.... and it still rendered right, mmmmm? Whereas on my working machine it didn't. Mystery.