Synced Normal Map Workflow, Has Anyone?

[Sonya Ying]

So this was a breif but hot topic about 2 years ago when materials was in its infancy.

Has anyone worked out a solid answer if synced tangent workflow is possible for normal maps on Second Life?, working very low poly and trying to rely on normal maps to produce hard edges is a nightmare on SL.

There's a quote from Geenz Spad (of Exodus Viewer) on the JIRA that suggests it is -impossible- due to a specific limitation in SL's code.

But given we have access to the source code, has anyone shed light on a confirmation,  work-around or has the expertise to counteract the issue entirely?

[MIstahMoose]

Could you give an example as to what you're doing/ Trying to do?

If I recall its not really the best practice to try and make a hard edge from a normal. Usually theyre used to soften edges. Since why take a soft edge and make it a hard one via normal mapping when you could just remove geometry to do so. As vice versa you save memory by reducing geometry while keeping your soft edge via normal.

[Sonya Ying]

that's only part of the story, really it's most common for game engine models to be either completely smoothed, or mostly smoothed with the normal map providing corrections for flat surfaces and realistic looking hard edges (actual hard edges on second life are technically splits in the model which have an infinately (read: float) thickness and produce breaks in the specular highlight.

The thing that makes game engines/renderers able to translate all this smoothing into a crispy clean surface from a normal map is a type of calculation which differs slightly between engines called a 'Tangent Basis', or more specifically syncing the normal map to match the variation used within the engine in question, honestly this is a huge field of study i'd suggest you look to more exhaustive sources (such as polycount's wiki) if you have a strong interest.

As for an example, I'll make some pictures the next time i log on for people who may be familiar with what it is but simply don't know the terminology used here.

[arton Rotaru]

AFAIK, the situation is the same as 2 years ago. At least I'm not aware of any XNormal plugin, or something, to sync normal maps with Second Life.

The best results are still achieved with the UnityTSpace plugin for XNormal, or by converting OS normal maps with Handplane to Unitys tangent space.

Depending on the geometry, editing vertex normals can improve the baking/shading as well.

While it would be cool if we could use soft edges only with normal maps, there is still the problem with people who don't have Advanced Light Model enabled. For these people, a completely smooth shaded mesh would look like a piece of old chewing gum in most cases.

IMHO it's best to do some compromises here. Hence having hard edges here and there to improve the shading without normal maps. Which helps minimizing shading errors with normal maps also.

The use of hard edges makes the creation of LODs easier as well (maintaining the shading across the leves).

Anyhow, IMO it should be possible to create a tangent space calculation plugin for XNormal with the SL viewers source.

Sadly that's beyond my coding skills, or I would have tried it myself already. :matte-motes-dead:

 

[Sonya Ying]

Basically this, that confirms with such disappointment, ah well, but thanks for confirmation.

It always seems like 50% of second life is trying to work around all the unfinished features, clunky land impact system, disappointing lighting and as you say the disparity of advanced lighting vs non-advanced lighting on models.

Who knows, maybe someone on SL has the coding expertise to make that plugin.

[arton Rotaru]

Yeah, it's weird to implement normal maps without providing a proper baking workflow. If they had just used MikkTSpace where the industry is finally heading now, all would be good.

I only hope they don't make the same mistake again with Project Sansar. :matte-motes-mad:

[Sonya Ying]

You can't help but want to ride that hype train all the way to the bank when it comes to sansar, the whispers about it make you feel like an artistic kid in a... well metaphors.

The history of how SL has been handled and developed doesn't fill me with confidence though honestly, maybe that's just all the negativity talking though. think positive damnit.

*Gets back on the hype train.*