Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Jpjapers on 2019-09-26, 16:33:36

Title: What would be the correct way to blend 2 normal maps together?
Post by: Jpjapers on 2019-09-26, 16:33:36

I have a fabric normal map and a wrinkes normal map and keep finding myself needing both.
What would the correct Gamma and blend mode be to mix them properly?

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: romullus on 2019-09-26, 21:30:54

In photoshop we use overlay to blend multiple normal maps, so the same should work in 3ds max too.

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: Jpjapers on 2019-09-26, 22:25:54

Quote from: romullus on 2019-09-26, 21:30:54

In photoshop we use overlay to blend multiple normal maps, so the same should work in 3ds max too.

Would I need to load them gamma 1.0 yes?

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: jms.lwly on 2019-09-27, 10:36:30

The Corona Material library actually has some materials with blended Normal maps (e.g. Fabrics).

They tend to go Bitmap -> Mix -> Corona Normal -> Triplanar (if required)

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: maru on 2019-09-27, 16:47:12

I think just blending them with 50/50 transparency should work fine, without any special blending modes.
Gamma should be the same as when loading just a single bitmap (so the brightness of the flat blue areas should not change).

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: Ricky Johnson on 2019-09-27, 18:10:05

There is supposed to be a technically correct method that requires treating each channel separately.
Lots of guides are available for different applications - Like this one: https://www.moddb.com/groups/udk-developers-group/tutorials/photoshop-combining-normal-maps
I don't know if the same set up could be replicated within a material in 3ds max - it would be complicated. The blend mode overlay always looked okay to me for a simpler set up.

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: Jpjapers on 2019-09-27, 23:52:35

Thanks for the information everyone :) I would have thought using a 50/50 mix would half the intensity of both maps overall so the strength might need to be doubled. I have an idea on how to do the photoashop method in max. It might be complete overkill and yield the same results but damn its got me curious to see if it can be done.

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: arqrenderz on 2019-09-30, 00:11:29

I make a  corona normal and in the additional slot i put another corona normal map (is it bad?)

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: romullus on 2019-09-30, 10:12:40

Quote from: arqrenderz on 2019-09-30, 00:11:29

I make a  corona normal and in the additional slot i put another corona normal map (is it bad?)

My feeling is, that it's really wrong, but it would be interesting to compare it to overlay blending method and see how it looks.

Title: Re: What would be the correct way to blend 2 normal maps together?
Post by: mantaskava on 2019-10-01, 09:16:24

Until recently I've just mixed them both with 50/50 (maps loaded as gamma 1) method and after that bumped up the strength from default value of "1" to "2" to compensate for the loss.
But now I got confused after watching some of the Adan Martin videos. Where he's disabling one's of the maps blue channel before mixing them, link to that video (and exact part) here- https://youtu.be/vAHLNq77jUs?t=1849 (https://youtu.be/vAHLNq77jUs?t=1849)

Anyone has any explanations/comments on this?