Jump to content
Sign in to follow this  
animats

Shinyness vs. lighting

Recommended Posts

I've been building something with a wood texture. I gave it low shinyness so that it looks like varnished wood. In most lighting, this looks fine. Midday, sunrise, sunset, midnight with white lights nearby, fine. But in New Babbage, it looks metallic.

New Babbage light is very diffuse. So anything with specular reflection gets something to reflect. The result looks metallic.

What's best practice for varnished wood under diffuse lighting? Or am I asking too much of SL's lighting model?

Share this post


Link to post
Share on other sites

i stressed this a lot in the past, so here we go again...

the use of materials does NOT end with normal map and specular map. A normal map's alpha drives the glossiness (aka specular exponent) and the specular map's alpha drives the environment, then these value maps get modulated by the numeric value found under the texture/shininess tab.

you may read "environment" as the pbr's metallic, for which a value of 1 means "reflect the environment" and a value of 0 means "don't reflect the environment". Therefore, guessing that you're using a fully opaque texture, you're telling the render engine that this material is metallic and as such it reacts to a more diffuse lighting.

in order to use the alpha as a map and keep the rgb values, task for which png doesn't suffice, you need to save your image ad tga 32 bit.

  • Thanks 1

Share this post


Link to post
Share on other sites

shiny shiny

have you had a look at https://docs.unity3d.com/Manual/StandardShaderMaterialCharts.html
your problem is the "color"
The specular colour that is which will be the colour reflected back when light hits - by default this would be white which can make things look a tad metallic.  You need to experiment with shades 
https://www.flickr.com/photos/galleriedufromage/shares/Dt7a45  shows the defaults of using white in the color and changing just the shininess value and and then the same thing changing the color from white to varying shades of grey all the way down to black, black meaning no shine whatsoever. 

Specular materials are often misused and misunderstood 
 

  • Thanks 1

Share this post


Link to post
Share on other sites
14 hours ago, Frenchbloke Vanmoer said:

your problem is the "color"
The specular colour that is which will be the colour reflected back when light hits - by default this would be white which can make things look a tad metallic.  You need to experiment with shades 

This clashes with any definition of a specular/glossiness workflow, and here is the demonstration rather than a link to obscure to the most folks documentations.

Substance Designer:

Screenshot_1.png.900c52b491ba1f746c0bf3f100f3fd91.png

Screenshot_2.png.af4f31c5e35d4e61bb3a396df2d4cea3.png

here there's a blending of materials, the top is gold, the bottom is a green plastic. On the right hand side, there are the output textures for a spec/gloss texturing workflow. Notice: on top there's the Diffuse, then Normal, Specular, Glossiness and height map (which we'll neglect). The glossiness map shows no division because the base materials were set to the same value

Screenshot_4.png.201aaaaaa61cbd60e32f38f8ff1baa7b.png

As you can see, whatever is metallic has NO diffuse component and its color is being driven by the specular color.

Screenshot_3.png.2664ef72b07c91a73845f6ff24ebcd78.png

All dielectric AKA non metallic materials always have a specular map set as a shade of grey and its color is left in the diffuse. The metals are black in their diffuse components to mark per-pixel metalness, and this can be seen in any renderer that uses blinn-phong based shaders.

Now, this partially happens in SL. To keep the legacy textures from breaking, LL did a sort of hybrid with the metallic/rough workflow. The regular diffuse color textures were maintained, however they needed some way to mark per-pixel metalness, which ended up being the Environment Map (SL's specular map's alpha) so that the diffuse color textures (different from just diffuse, a diffuse color is the result of lighting) could be kept and act as a basecolor map (in the metal/rough workflow), have a blinn-phong compliant specular color map and get the legacy shininess setting (the metallic look) operate on a per-pixel basis using the Environment map provided with the specular maps' alpha channel.

Therefore, NO, you don't have to fiddle with color in the specular map for a non-metallic material and its lack of colorization doesn't give it a metallic look. 

14 hours ago, Frenchbloke Vanmoer said:

by default this would be white which can make things look a tad metallic

As a further note, you may inspect the specular map's levels. Metallic materials levels range slightly beyond 0.5 (or 127) while non-metals range slightly below this value (reason for a specular level map to exist in a few rendering engines)

14 hours ago, Frenchbloke Vanmoer said:

Specular materials are often misused and misunderstood 

Exactly.

  • Thanks 1

Share this post


Link to post
Share on other sites

When it comes to second life everything that is straightforward in every other pbr enabled world is rather less than straightforward. 

A lot of downright cheating is involved. Try to make a semi transparent liquid that reflects the environment.  Not going to happen unless you cheat. 

The only time I have seen metal actually look metal is with an environmental cube mapped projection. 

"shininess" is seen as a gimmick. Which is why you'll see shiny wool, shiny carpet, shiny stone, shiny everything.  And usually either set to 51 by default or whacked up full. 

Getting things to look halfway right once you've rezzed it and got the windlight /lightning correct is a win 

What looks "ooh" in Substance can look ".. Oh.." in second life. 

Not everyone has experience of 3d engines beyond Linden Labs and just want things to look how they want it to. So giving them the knowledge that white =shiny, black =no shine at all and everything in between is everything in between is often enough to get people experimenting and trying it for themselves. 

 

  • Haha 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...