Corona Renderer Forum

Corona Renderer for Cinema 4D => Corona Renderer for Cinema 4D - general => Topic started by: kmwhitt on 2019-03-30, 01:21:17

Title: Exaggerated Normal
Post by: kmwhitt on 2019-03-30, 01:21:17
I'm working on a visualization where I need a very subtle brush stroke on some painted trim.  It works great everywhere except the trim towards the ceiling - see attached.  I can't help but think this is a bug as it looks great in all the other shots.  I created the normal map in Substance Designer using DirectX which has always worked for me - normal map also attached.  There are no overlapping polygons.  The phong tag is not an issue as I have the same problem without the phong tag.  I have tried changing the camera angle slightly and get the same problem.  I have tried everything I know to do.  Anyone got any ideas?  Also, I thought at one time we could decrease the normal intensity by lowering the strength percentage under bump.  Even at 1% I get the same ugly artifacts.  I would really appreciate any advice as I need to finish this project over the weekend.  Thanks!  Kevin
Title: Re: Exaggerated Normal
Post by: kmwhitt on 2019-03-30, 01:25:21
Here's a pic of how the brush strokes look in Sub Designer.  This is exactly what I'm looking for and in the past have gotten a perfect match in Corona C4D. 
Title: Re: Exaggerated Normal
Post by: kmwhitt on 2019-03-30, 01:40:47
Attached is an image of the normal channel.  I've always used the default settings with maps exported from Sub Designer with no problem.
Title: Re: Exaggerated Normal
Post by: spawnik on 2019-03-30, 21:49:19
Try to set the normal bitmap color profile to Linear and crank down bump value.
Title: Re: Exaggerated Normal
Post by: kmwhitt on 2019-03-30, 23:03:37
Spawnik - it's already on linear and as stated above lowering the bump intensity has no effect.  I have run into this before with Vray where the normal does not behave correctly due to the viewing angle of the camera.
Title: Re: Exaggerated Normal
Post by: kmwhitt on 2019-04-02, 01:23:24
No comment/feedback from support?  No request for the file?
Title: Re: Exaggerated Normal
Post by: Gruender on 2019-04-02, 10:09:59
You need to flip green too.
Title: Re: Exaggerated Normal
Post by: kmwhitt on 2019-04-02, 11:45:30
Gruender - thanks for the input.  I have never had to change the settings in the past.  Also, the normal behaves as expected everywhere else with the default settings.  I would appreciate some advice from the developers on this problem.  I asked the preferred settings using DirectX generated normals months ago in this thread:  https://corona-renderer.com/forum/index.php?topic=17406.msg109394#msg109394 and never got a response from support - you yourself participated in this conversation.  It would be nice to put this finally to rest and be given the correct use of DirectX normals from the team that wrote the plugin.
Title: Re: Exaggerated Normal
Post by: kmwhitt on 2019-04-03, 15:54:26
Houska - would you please provide some input regarding this post and the proper settings for DirectX normals?  I can provide the file if you think this might be a bug.  Thank you.
Title: Re: Exaggerated Normal
Post by: houska on 2019-04-03, 16:21:44
Hi kmwhitt,

it seems like you are using an OpenGL normal format, so just check the "Flip Y (green)" checkbox. With default settings (all unchecked), the Normal map interprets the textures as DirectX normal maps.

At least it seems so from all the topics here on the forums... To be honest, I don't remember from the top of my head which of the conventions is DirectX and which one is OpenGL.

Edit: I just read that you are using DirectX normal format... In that case, I don't know what could be causing your issue. Maybe flipped UVW coordinates? In any case, if you still have issues with it, we will be happy to have a look at your scene of course.
Title: Re: Exaggerated Normal
Post by: kmwhitt on 2019-04-03, 18:12:32
Thanks Houska.  I will simplify the file and upload tonight.
Title: Re: Exaggerated Normal
Post by: romullus on 2019-04-03, 19:34:42
To be honest, I don't remember from the top of my head which of the conventions is DirectX and which one is OpenGL.

OpenGL is +Y and DirectX is -Y. Visually, if normal map looks about right (e.g. bricks are extended outward), it is OGL, if it looks inverted, then it's DX.
Title: Re: Exaggerated Normal
Post by: nkilar on 2019-04-04, 00:17:07
Hi kmwhitt,

it seems like you are using an OpenGL normal format, so just check the "Flip Y (green)" checkbox. With default settings (all unchecked), the Normal map interprets the textures as DirectX normal maps.

At least it seems so from all the topics here on the forums... To be honest, I don't remember from the top of my head which of the conventions is DirectX and which one is OpenGL.

Edit: I just read that you are using DirectX normal format... In that case, I don't know what could be causing your issue. Maybe flipped UVW coordinates? In any case, if you still have issues with it, we will be happy to have a look at your scene of course.

Just thinking out loud here but maybe it would be good to have a small text field saying exactly this. Similar to what is already done inside the Normal map shader.

I know nobody wants a wall of text in there but I continuously get confused about what to flip - I can't imagine someone who is just starting out and his confusion level. Maybe its just me :)
Title: Re: Exaggerated Normal
Post by: houska on 2019-04-04, 09:20:16
Just thinking out loud here but maybe it would be good to have a small text field saying exactly this. Similar to what is already done inside the Normal map shader.

I know nobody wants a wall of text in there but I continuously get confused about what to flip - I can't imagine someone who is just starting out and his confusion level. Maybe its just me :)

Good point. We will think about that! There's already some text, so adding yet another line is OK