PDA

View Full Version : Material node specular



Musart
03-22-2016, 04:49 PM
Hi to all,

I'm wondering about the material nodes (Delta, Conductor) specular from light.

As you can see, the first image is Delta node 100% specularity, 20% Roughness (Ref blur on) but it doesn't seem to reflect light as seen in the next 3 images. Do I use the delta node the wrong way?

The 2nd image is from the STD surface settings, 100% specular, no reflection.

The 3rd picture is the STD surface settings, 0% diff, 100% Spec, 100% reflection (Blur on)

The 4th image is from Blender Cycle, 100% Gloss with some roughness.

133048133046133047133049

Delta node setting (simple though!)
133050

djwaterman
03-22-2016, 05:33 PM
I think that should be correct depending on what type of light you are using. If you use a DPlight (http://dpont.pagesperso-orange.fr/plugins/lights/Additional_Lights.html) light they will provide a light reflection that the LW lights don't. Delta by it's nature is not using fake specular, specular means reflection in the delta node.

Thomas Leitner
03-23-2016, 02:20 AM
I think that should be correct depending on what type of light you are using. If you use a DPlight (http://dpont.pagesperso-orange.fr/plugins/lights/Additional_Lights.html) light they will provide a light reflection that the LW lights don't. Delta by it's nature is not using fake specular, specular means reflection in the delta node.

Hi,
Delta uses fake specular too and the LW lights provide a light reflection.


...As you can see, the first image is Delta node 100% specularity, 20% Roughness (Ref blur on) but it doesn't seem to reflect light as seen in the next 3 images. Do I use the delta node the wrong way?....


As mentioned: Delta uses fake specular for lights. 20% Roughness is a high value, try to reduce it.

ciao
Thomas

Musart
03-23-2016, 05:34 AM
Thank you for the feedback.

I'll make some tweak to figure out.

Musart
03-23-2016, 06:03 AM
Lightwave lights does indeed reflect.

It does depends on the object edges geometry, roughness amount and the light size. I refined my test model to have more rounded edges than it was.

1st image is stock Sphere light @ 100mm and the second image is @ 800mm.

Thanks again.


133061133062

S0nny
03-25-2016, 08:15 AM
Hi to all,

I'm wondering about the material nodes (Delta, Conductor) specular from light.

Yes, specular component in lw materials is like like 25-50 times weak, depending on the scene and distance from source.
You should use material tweaker, which is a 3rd party free plugin node from DB&W, between delta and output, with 25-50x boot in specular and it will fix the problem.

Edit: here's a screenshot with the basic setup. As you can see from the small preview, the spot highlight is barely visible in the delta but appears after the boost.

133112

spherical
03-25-2016, 01:50 PM
Yes, specular component in lw materials is like like 25-50 times weak

Actually, they're correct. The perception may be that they are weak, but that's subjective. The materials are designed according to the equations. I use Material Tweaker or Material Booster in special cases, where it helps to provide "what the eye expects to see", but I use them sparingly and not much of a boost at that. Mostly, I leave Specular at default and boost Reflection a bit; which in real terms IS Specular. LightWave's specular is a shortcut hack. It's a reflection or it isn't.

Tobian
03-25-2016, 05:25 PM
Nope they are totally wrong. Lightwave specular is calculated as if it were the same intensity as the diffuse, which is also kind of wrong in a lot of ways too, either way the intensity of one or the other is incorrectly computed, so in either case specular is plain wrong. The way that light intensity is calculated is part of the problem, where you define it's intensity at a nominal distance from the light it's self, rather than the lights emissive surface (in the case of area lights of course), and there is no correlation between the size of a light and it's intensity as well, which means lights themselves are somewhat of a fudge in general.

A simple fix is to either use Reflection only (which is problematic, I know) or as S0nny says boost the specular to help compensate for how weak it is, relative to the diffuse, but sadly this has to be done by eye, as there's no real formula to use, because the boost to the spec should be being handled in the light, but there's no way to do that that I know of.

S0nny
03-25-2016, 06:08 PM
A simple fix is to either use Reflection only (which is problematic, I know) or as S0nny says boost the specular to help compensate for how weak it is, relative to the diffuse, but sadly this has to be done by eye, as there's no real formula to use, because the boost to the spec should be being handled in the light, but there's no way to do that that I know of.

Exactly, but I should thank and credits you and the other guys for the tip. I remember reading very old discussions about this - and other similar stuff here on the forum - and that changed the way I build my materials in lw since then.

Tobian
03-25-2016, 06:34 PM
Fingers crossed they have fixed this with the next version of LW, with it's 'PBR' system (no idea what that really means yet). and you're welcome :)

S0nny
03-26-2016, 02:54 AM
Fingers crossed they have fixed this with the next version of LW, with it's 'PBR' system (no idea what that really means yet). and you're welcome :)

I really hope so, I can do almost everything I need with lw engine, but it's some time already it feels like working with a disadvantage or a penality.