Where can I learn what I, as a user, not a creator, need to know about materials?

[Jennifer Boyle]

The whole question is in the title. I have searched help, answers, and the forums, and not found the information I seek. The FAQ is directed at creators and has no information about what materials do.

[Chic Aeon]

There isn't a lot that you need to know about materials as an end user.

1. only folks with Advanced Lighting enabled can see materials. For those with lower settings or ALM off by choice, there will be no difference between items with materials and those without.

2. materials come in two ways in SL. Specular (shine that changes dependent on the direction of the light source) and Normal (a bumpy look also dependent much on the light source.

3. materials can add to the realistic look of an item by giving 'faux' details (in the case of normal maps) but can look very bad in some lights. A trade off.

4. some of the "bump and shine" of materials can (and was before they were added to SL already available) by baking textures within a 3D software program.

5. IF your computer is strong enough to use ALM then you can go to some creators that advertise materials and perhaps get a demo (hair oftentimes comes with and without materials) and see which you prefer.

Those are the main points I think. There are likely others. Some folks like materials, others do not. I typically lean to the "not" side as they add an extra texture download and can really look bad in some Windlight settings. As a creator I frequently use them on METAL (the specular part) to replace the old "low" shine that we had before. They can also be adjusted by the creator (or the customer if an item is mod) within world. 

[Lillith Hapmouche]

Visuals:

from https://minahairfashion.wordpress.com/materials/

[Qie Niangao]

I'm not sure whether the OP got all the answer she wants "as a user, not a creator" because it's not clear how much interest there may be in tweaking what creators have already done.

First, though, it's important to appreciate that the two most common Materials features, normalmaps and specularmaps, when properly applied will cause surfaces to respond convincingly to changes in lighting and camera position. That's in contrast to the old baked lighting approach, which forever freezes shading into a surface texture according to lighting conditions that will never be completely consistent with the lighting of any in-world scene, and will look weirdly static as the camera moves around the object. (Well, "weirdly" if one is not already accustomed to it, as we all are after seeing it for years.) In theory, baked lighting effects can be more precise (for that one static lighting condition) because the external program can use an arbitrarily long rendering time whereas the viewer must render SL Materials in real time -- but personally I've never really noticed that advantage whereas the disadvantage distracts me every time I move my camera.

Anyway, a normalmap results in surface shading almost as if the grain in the normalmap were in the model, but way, way more efficiently than representing all that detail in the model itself (and better in every way than the old "Bumpiness" effect). Specularmaps apply different amounts of shininess to different parts of the surface -- but even a "blank" specularmap allows applying some uniform shininess to surfaces with much more realistic and flexible effect than the old simple "Shiny" settings.

Also, there's more to SL "Materials" than Normal- and Specularmaps. Two other features are the Alpha Modes "Masked" and "Emissive". The first of these simultaneously reduces rendering complexity and defeats the nasty old "alpha-sorting" problem of more distant semi-transparent surfaces popping in front of nearer surfaces. The downside: any pixel in an alpha-masked surface is either fully opaque or fully transparent, so there's no seeing through it as a translucent surface. Also, this makes the edges between opaque and transparent very stark, so it may not always give the desired effect (wispy foliage, for example).

Emissive alpha mode doesn't involve regular transparency at all, but instead uses the alpha channel bits to code for how different parts of the surface appear to emit their own light -- much like a "full-bright" texture but not for the whole surface, and potentially a gradation of that effect. For example, I've used it make the top part of a candle full-bright and gradually shift to a regular, non-emissive surface further from the flame. This is an extremely cool and underutilized feature, but one that I'd expect to be of more interest to creators than users -- although I have tweaked some purchased items that really needed the effect (and for which I could fake the diffusemap texture image).

Big caveat: Applying any of these Materials features forces immediate "mesh accounting" of Land Impact -- which can cause a disastrous inflation of LI for some relatively innocent-seeming prims. To be safe, don't play with Materials except on a copy, in a sandbox (or attached).

[Chic Aeon]

43 minutes ago, Qie Niangao said:

Emissive alpha mode doesn't involve regular transparency at all, but instead uses the alpha channel bits to code for how different parts of the surface appear to emit their own light -- much like a "full-bright" texture but not for the whole surface, and potentially a gradation of that effect. For example, I've used it make the top part of a candle full-bright and gradually shift to a regular, non-emissive surface further from the flame. This is an extremely cool and underutilized feature, but one that I'd expect to be of more interest to creators than users -- although I have tweaked some purchased items that really needed the effect (and for which I could fake the diffusemap texture image).

Didn't know that and will give it a try as I am not a big fan of full bright :D.

And while I am not really fond of materials because of the horrible way they can look in some Windlight settings (normal maps mostly) I do agree that baked textures (which I love :D) can ALSO be very ugly if they are not done correctly.

So as both consumers and creators we have to decide what we like and why and when to use materials.

 

[Pamela Galli]

Most of the time when I see how normal maps look, I leave them off. I like spec maps but depending on the windlight they can come out looking too shiny in some locations, so it would be good for consumers to know how to adjust them.

[Chic Aeon]

42 minutes ago, Pamela Galli said:

Most of the time when I see how normal maps look, I leave them off. I like spec maps but depending on the windlight they can come out looking too shiny in some locations, so it would be good for consumers to know how to adjust them.

Well for H and G where folks can normally SEE what they are buying (or at least have the opportunity to if they aren't lazy *wink*) they can look and hopefully tell if the products will work for them.  I very seldom use normal maps for reasons stated and I do think it would be good for folks to know how to adjust or turn off. When materials were new, I usually had a "materials" version and one that wasn't for the people who didn't know how to get rid of them if they wanted. Now of course since I am no longer using them all that often it isn't an issue.