Speculars are non-optional

[Imrinfected]

It really bakes my potatoes to see so many people making normal maps without speculars in them. It's not optional - if you don't include one, then the object will look very glossy, which is almost never how it should be.

 

If you didn't already know, the specular map is a grayscale image which is contained with in the Alpha channel of the normal map, and it determines how light reflects off of an object. They're a great way to add subtle detail and greatly enhance texture quality, but they need to be done properly. Typically you can just use a grayscale version of your diffuse with the levels altered, but often times and usually for better results it's necessary to do further editing for fine detail.

 

They're very simple to make, and disappointingly it seems most people are overlooking their usage.

 

Another important note is that most textures need to be seamless. Skyrim reuses many textures for many different objects, with the exception being seemingly all equipment and misc items. If the textures aren't seamless then they will look very ugly in-game, as they repeat and visible seams make them look very bad. Making a texture seamless is a very simple process - just cut the texture into a 4x4 grid, flip all of the sections, and then either meticulously use various tools to fix the seams, or do a quick job with the healing brush tool or clone stamp tool(or non-photoshop equivalents).

 

Altogether it would be maybe an additional 5 minutes per texture for superior quality.

 

Also, when using the healing brush tool or clone stamp tool, do not sample the same section of the image more than once or it becomes very repetitive and ugly.

 

Lastly, for Talos' sake, do some tutorials. I see so many very easily avoidable mistakes in textures that would otherwise look very good with basic knowledge.

 

EDIT: When you use the Nvidia normal map filter, keep in mind that black is depth and white is height before converting it. It uses those two values to determine the depth and height, so be sure to actually edit your diffuse before using it. A good rule of thumb is to use a high-pass filter first to eliminate the unwanted shading that would cause strange results, and use the burn/dodge tool to add fine details for the normal map filter. When you convert it, it may(and probably will be) inverted, so either convert it with Y inverted, or invert the Green channel after you convert it. Depressingly, I see a lot of normalmaps that indent where they should extrude, and it's such a simple fix to avoid that.

 

EDIT 2: Upscaling and sharpening a texture does not add detail. In fact, higher resolution does not necessarily mean detail either. There is a maximum texture resolution which you will benefit from depending on your resolution, and for many people textures that are 4096x4096 are just wasted VRAM. For example, assume that a texture is (unconventionally and unrealistically, for the purposes of simplification) 1000x1000, and that your screen resolution is 1000x1000. If you are in 100% view of that texture, you are getting the maximum and optimal benefit from that texture. With a resolution of 500x500 however, at 100% view of that texture, half of that texture resolution and thus vram consumed from it goes completely to waste. Please keep this in mind when making textures. At a distance, pixel ratio is smaller, so distant objects should not have high-res textures, or high-poly models for that matter. In fact, that's why this game uses LOD swaps in the first place. So things like the roofs of houses, chandeliers, places not easily reached by the player for closer inspection, should be a lower resolution than say, the ground, which they are almost always very close to. What's more, the demand for retextures is chiefly for high-resolution textures, in the 2048x2048-4096x4096 range, so anything less than that will go largely unused.

 

Never downscale a normal map, by the way. You will get artifacts and strange results. You may downscale the diffuse and maybe the specular depending on the algorithm(although not the best practice), but never the normal. Similarly, you can never upscale any image and get better quality - it's impossibly by the fundamentals of reality, and more directly the laws of thermodynamics(Law of conservation of energy, namely) to create more from less, and this stands true with data.

 

The normal map filter is also not the best way to create a normal. Conventionally you would use a normal baked from a high-poly version of a low-poly model on the low-poly model. That requires considerably more time, however, and the quality improvement is really not good enough to be worth it(at least for the purposes of modding pro bono).

Edited November 21, 2011 by Imrinfected

[cojaca2]

To be fair, Bethesda games have some ridiculously shiny textures to begin with, but I agree.

[Imrinfected]

To be fair, Bethesda games have some ridiculously shiny textures to begin with, but I agree.

Depressingly, that's true. I'm reminded of Doom 3, where everything looked to be made out of some intensely shiny material - skin, metal, it made no difference. How supposedly professional texture artists are able to make such bad specular maps(or textures in general) is astonishing, but I suppose in Bethesda's case that would be because (evidently) a person doesn't actually have to be competent or have any range of experience to work there.

 

With that said, quality of everything in Skyrim ranges from amateur "My first retexture" quality work to very professional and well-done work. It's like Todd Howard is actually Sheogorath and really just wants to mess with everyone who plays Bethesda games, making them wonder "What the hell were they thinking?"

[throttlekitty]

+1 for this!

 

I'd also like to add that if you're adding detail in a normal map, please be aware of what details you're putting in. Nothing worse than seeing a diffuse map >normal map filter, and getting bumps where a reflection was painted. Or the 'Puffy Paint' effect coming from any kind of lettering/logos on what would otherwise be a flat label on a bottle.

Edited November 21, 2011 by throttlekitty

[Imrinfected]

+1 for this!

 

I'd also like to add that if you're adding detail in a normal map, please be aware of what details you're putting in. Nothing worse than seeing a diffuse map >normal map filter, and getting bumps where a reflection was painted. Or the 'Puffy Paint' effect coming from any kind of lettering/logos on what would otherwise be a flat label on a bottle.

Agreed. I think before using it, people should be aware of how it works.

[Ghogiel]

I agree with all that.. except downscaling a normal map. For a long time I was probably thinking what you are thinking, ie because if you downsize the pixels get resampled according to adjacent ones, in theory giving you slightly incorrect or bent normal. However pretty much all my favourite game artists have said you can render at twice the resolution and resize, and in fact they do so to add extra AA to their baked normal.

 

Since I started doing it I haven't noticed any problem... wouldn't matter one tiny bit if you compress the normal map anyway, it's going to destroy it way more than a resize

 

http://wiki.polycount.com/NormalMap#Anti-Aliasing

 

it's on the wiki... so it's gotta be good info.

Edited November 21, 2011 by Ghogiel

[Deleted2039153User]

I agree with all that.. except downscaling a normal map. For a long time I was probably thinking what you are thinking, ie because if you downsize the pixels get resampled according to adjacent ones, in theory giving you slightly incorrect or bent normal. However pretty much all my favourite game artists have said you can render at twice the resolution and resize, and in fact they do so to add extra AA to their baked normal.

 

Since I started doing it I haven't noticed any problem... wouldn't matter one tiny bit if you compress the normal map anyway, it's going to destroy it way more than a resize

 

http://wiki.polycount.com/NormalMap#Anti-Aliasing

 

it's on the wiki... so it's gotta be good info.

 

This is correct. In practice you should be making your maps (any map, not just normals) as large as you can without it becoming difficult to work with, and then scale down if necessary.

 

It's one of the unwritten rules of texture design in game art: Start big, scale down. You can scale something down easily, but you can't scale up easily if you need it to be bigger.

[Ghogiel]

I agree with all that.. except downscaling a normal map. For a long time I was probably thinking what you are thinking, ie because if you downsize the pixels get resampled according to adjacent ones, in theory giving you slightly incorrect or bent normal. However pretty much all my favourite game artists have said you can render at twice the resolution and resize, and in fact they do so to add extra AA to their baked normal.

 

Since I started doing it I haven't noticed any problem... wouldn't matter one tiny bit if you compress the normal map anyway, it's going to destroy it way more than a resize

 

http://wiki.polycount.com/NormalMap#Anti-Aliasing

 

it's on the wiki... so it's gotta be good info.

 

This is correct. In practice you should be making your maps (any map, not just normals) as large as you can without it becoming difficult to work with, and then scale down if necessary.

 

It's one of the unwritten rules of texture design in game art: Start big, scale down. You can scale something down easily, but you can't scale up easily if you need it to be bigger.

Actually...sort of. When rendering yes. but painting not exactly. painting 1:1 on the diffuse and other maps has a bit of advantage in finer control, in that resampling does impact the final textures pixels, not always for the better. There is a whole debate going on about this. The idea is that with that 1px brush you have very fine control and AA is not a concern at that point because you are painting. Some artists, moreso ones working on games who have quite restricted texture budgets, will work 1:1 at least for a final pass.

Edited November 21, 2011 by Ghogiel

[Valamyr]

It really bakes my potatoes to see so many people making normal maps without speculars in them.

 

Lots of great info in this thread, thank you :)

 

The fact that the pet peeve you had to share with us was specularless-normalmaps admittedly got a chuckle out of me, considering most people wouldn't know what either of these things are, but it's totally appropriate to mention here, especially given the amount of detail and advice you included.

[UberGrainy]

From personal experience, I can confirm virtually everything Imrinfected has said. Nice to see I'm not the only one noticing all the awful seams and that nobody is bothering to edit the specular maps. I've had to fix all of those myself. I don't know why, but it seems that people in general don't understand the concept of specularity/shininess, even at the game development college I graduated from. I've also noticed that Skyrim has lots of seam issues to begin with (as many large-scale games seem to).

 

I don't know if it's possible to do so, but I think it might be better to change the topic of this thread to "common issues with texture mods", otherwise most people will probably miss the topic if they don't know what "specular" means.

 

Some important notes:

- The specular maps in Skyrim are not always stored in the alpha channel. Some are stored in separate DDS files with a _S suffix.

- The trick I used to fix the seams was to overlay the modified texture over the original, then use modify selection to feather-delete the edges of the modified texture, so that the texture uses the original seams.

- Regarding upscaling, it may become viable depending on how effective Adobe's new filter will be. As far as I know, it hasn't been released to the public yet.

 

Hope this information helps.

Edited November 21, 2011 by UberGrainy