Mikk TSpace Normal shader

Project:YafaRay
Component:YafaRay Core
Category:feature request
Priority:normal
Assigned:David Bluecame
Status:postponed
Description

Blender's and Xnormal's standard MikkTSpace tangent space normal maps are not rendered correctly, likely a problem with the tangent space calculation.

Images attached, BI vs Yafa comparison.

Wanted to attach .blend, bug tracker won't let me - "The selected file yafanormaltest_s.zip could not be uploaded. The file is 667.29 KB which would exceed your disk quota of 1 MB."

Windows 7 x64, Yafaray 1.5.0 Stable, Blender 2.67b official

AttachmentSize
yafanormaltest_yafa.jpg39.89 KB
yafanormaltest_bi.jpg38.39 KB

Comments

#1

I do not see difference between both images.

Btw.., it is more practical to publish first these messages in the forum. There, more people can read them and contribute cross-checks and additional tests, before deciding if it is a bug, or a mistake of procedure.

#2

There's an announcement in the forums to use the bugtracker, so that's exactly what I did. I've seen this type of artefact often in games and it's almost always due to tangent space mismatch, so I'm pretty confident it's a bug. (Unless you've simply chosen to sync the normal map tangents with some other app, like Max or Maya, in which case providing an option to use mikktspace would still be desirable)

It's true that it isn't so easy to spot the problem areas just looking at them, but they're easy to see if you flip between the two images back and forth quickly. Also, only some of the triangles really show the error because there's always the chance that the mikktspace tangent and yafa tangent match by coincidence. Look closely at the side of the base and the panel just below the screen in particular.

You can grab the mikktspace tangent calculator here:

https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspa...

https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspa...

And read more about it here:

http://wiki.blender.org/index.php/Dev:Shading/Tangent_Space_Normal_Maps

#3

Priority:normal» critical

Can you please use dropbox to share the scene please or any cloud storage service?

My work · Grey18 workflow · Sampling strategy · [url=http://www.yafaray.org/node/816]SPPM

#4

File to test bug with:

https://www.dropbox.com/s/tpz3dib5ixepvn1/yafanormaltest.blend

My work · Grey18 workflow · Sampling strategy · [url=http://www.yafaray.org/node/816]SPPM

#5

Priority:critical» normal

#6

Title:Normal maps don't render correctly» Mikk TSpace Normal shader
Category:bug report» feature request
Status:active» postponed

Hello,

 

I think this cannot be considered a bug. From what I've read Mikk TSpace is a standard for Normal representation, increasingly becoming the industry standard. Blender uses it, acording to its documentation, but It has not been supported by many major render engines until recently.

Some interesting links:

http://3d-coat.com/forum/index.php?showtopic=16476

http://mari.ideascale.com/a/dtd/Synced-Normal-Maps-Mikk-TSpace-Normal-Ma...

http://www.polycount.com/forum/showthread.php?t=147125

etc.

 

So, I will consider this a feature request, and unfortunately it will be in the "postponed" list for now due to low time and resources to implement this.

#7

Assigned to:Anonymous» David Bluecame
Status:postponed» active

#8

Status:active» postponed