Leather sofa for material evaluation

[S0nny]

Hi guys,
I still have some problem with some materials so I decided to play with this simple scene I created. I think leather it's a difficult one, here is my attempt to create a material for the famous Chester sofa (BTW it's not modeled by me, it's a convertion from v-ray/max).

I like it, but I'm not satisfied yet, I don't know, there is something about reflection/blur in the leather not totally convincing... what do you guys think?
I'll finish this scene with other details here and there when I hav time.

[Janusz Biela]

Leather is no so much difficult to do. Difficult is to get nice reflection which comes from windows, lamps, etc. Without Nodes forget about this surface.
Here some informations (V-ray render):

- floor with Ani reflection and minimum 3-4 textures
- white metal chair with double reflection+multiply refletion
- metal Inox with texture which simulate dirt
- leather with minimum three textures: small bump, diffuse, big splotches mixed in Nodes with inverse reflection blur

I write it because you can do it also in Lightwave (of course in Kray not native render engine)...there is good surfacing done in Nodes and quality render. Both you can do in Kray.

I think you got really good quality...maybe one close-up please?

btw
You ruined render by ugly floor

[S0nny]

- leather with minimum three textures: small bump, diffuse, big splotches mixed in Nodes with inverse reflection blur

I write it because you can do it also in Lightwave (of course in Kray not native render engine)...there is good surfacing done in Nodes and quality render. Both you can do in Kray.

Yes everithing is nodal here because I can't live without now
The reflection is coming from LEMS, one on the left, one on the right.
I attach the node here, it's simple, I have some doubt on how to mix different images for reflection before the input: should I use add, multiply or what? Same if I want to mix more bumps or more diffuse: add, multiply, or ...?

I think you got really good quality...maybe one close-up please?

Thank you, this is a render with just some pp in Look! I'll do a close up

btw
You ruined render by ugly floor

Ahah yes you are right I'll fix it in the next render

[Janusz Biela]

...here solution (I mentioned this in Nodes topic):

- you start with one texture (only!...in some cases is enough one)

- color correction (Color Tool Node) for tweaking texture...you do not need waste time in Photoshop

- reflection tool (Color tool Node) is for preparing reflection map and connect it with Fresnel
(more white more reflection)

- reflection preview (DEFAULT color tool) is to see how looks map mixed with fresnel

- Invert for inversion map and after that next Color Tool for control (white more blure, dark less blur)

- Normal Map for bump and one extra Node Add which allow you mix 4 bump maps.

What you do only in "system" is choice texture, setup level of reflection, setup level of blur, setup level of bump....10-20 sec of job and fire

Of course you can mix 2-3 textures map by Mixer, colors with textures by Mixer (before is good to desaturate texture) and after that create reflection map or mix two reflection maps, making exclude for reflection, etc.

PS
For really good quality surfaces this Node is just starter...it can be situation when system will grow up 2-3 times more because some surfaces are really complicated and need to mix many textures...and there is no other way to do that - only Nodes.

[S0nny]

...here solution (I mentioned this in Nodes topic):
Of course you can mix 2-3 textures map by Mixer, colors with textures by Mixer (before is good to desaturate texture) and after that create reflection map or mix two reflection maps, making exclude for reflection, etc.

Ok, if I understang correctly I can use only mixer and decide inside mixer if is better add/multiply/subtract etc, so I mix everything before multiply with fresnel, seems right.
So this is the updated node:

[Janusz Biela]

In Mixer you can do everything, important is to achieve result. The most common is Multiply.
Important: better is when you use mixer system BEFORE splitting to reflection and blur (you need same map for reflection and blur, except the blur map should be inverted).

[S0nny]

Important: better is when you use mixer system BEFORE splitting to reflection and blur (you need same map for reflection and blur, except the blur map should be inverted).

Oh right! So the ref map is already mixed before the blur: do you mean like this?

[Janusz Biela]

no

Like this:

I mixed two reflection (this is just example) but before mixer I prepared them. After Mixer I used again color tool because I needed different level. In the end is clamp which keep my level between 0.0 and 1.0 (between RGB 0,0,0 and RGB 256,256,256)
This is also important because if you will add too much brightness you can be out of reflection range (150% reflection for example)
After this reflection system you go to Fresnel and blur.

Above also example how in few seconds make brown/green texture:
- Desaturate + levels (must be maximum acceptable level of brightness, this depends of course from what you want create)
- Mixing texture with color (can be done in many way depends what you need)
- after Mixer Texture Control levels, contrast, HUE.

Of course this is basic control and to receive very HQ texturing, system will grow.
Best artist in V-ray or another for example use much more complicate mixing but idea is exactly the same. You can not make good render with basic surfacing....THIS IS IMPOSSIBLE! and it means: if you do not know Nodes, forget about jumping to higher level. Forget about standard LW system (too many limits and too slow with construction)

System above is very easy, the same for all surfaces. It doesn`t mean you have to use it for all surfaces but you have to use for important part of render: in your case floor ( ) , wall, leather. Rest surfaces: metal, plastic, basic surfaces needs only basic Nodes.

One more think: why users from LW Native Engine Render could not do it? Of course they can, but only Kray in LW has really physical GI and these Surfaces Nodes looks much better in Kray then LW.

[S0nny]

Ok, that's make sense.
One more question: why you need to clamp the values just before multiply with fresnel and not after the reflection preview? If preview is used wrong can cause value >1... or not?

[Janusz Biela]

Ok, that's make sense.
One more question: why you need to clamp (I suppose 0.0 min and 1.0 max) the values just before multiply with fresnel and not after the reflection preview? If preview is used wrong can cause value >1... or not?

yes, if you make brightness very strong on texture by Color Tool , it can be situation >1 (over 100% reflection) so better use Clamp after color tool before multiply with Fresnel to be sure. Also in the end of system you have Clamp Node (reflection/diffuse) to be "sure of sure" you did not over jump physical values.

[S0nny]

Ok, I'll do some experiment, I think I'll start with the floor

[S0nny]

So, this is a small update with leather and floor updated. The close up is risky because it's not so detailed, but I like it much better than the first render anyway.
Any suggestion about materials are welcome!

edit: maybe the leather needs to be a bit more blurried

[Janusz Biela]

Yes you drift in correct direction! Same system for floor.
I hope you do not use specular this is really old technology ...and this effect doesn`t exist in real world

G. almost finished K3 plugin for Lightwave (he delayed for next week beta release) I say about this, because with Kray VPR will be much easier setup Nodes

I suggest to fix the floor and add small table on the side with lamp. It will give boost for render and also will be good to test render with extra light source. One hint: do not try illuminate this scene with bulb. This surface should be faked or with low Luminescence (bulb LEM ~300% luminescence with ~3500 K temperature) Real light should come from Spherical Light which is around LEM bulb. The noise control for Lightwave Spherical Light is in QUALITY TAB - Luminosity Threshold and minimum value for that should be 100/0:

[S0nny]

Yes you drift in correct direction! Same system for floor.
I hope you do not use specular this is really old technology ...and this effect doesn`t exist in real world

Don't worry I've banned specular a long time ago
The white reflection you see is coming from white LEM panels (3 in total, left, right, top) and white backdrop, no other lights are involved (for now).

G. almost finished K3 plugin for Lightwave (he delayed for next week beta release) I say about this, because with Kray VPR will be much easier setup Nodes

This is a good news, finally! Vpr for kray can save tons of hours of trial<->error, in production is a MUST.

I suggest to fix the floor and add small table on the side with lamp. It will give boost for render and also will be good to test render with extra light source. One hint: do not try illuminate this scene with bulb. This surface should be faked or with low Luminescence (bulb LEM ~300% luminescence with ~3500 K temperature) Real light should come from Spherical Light which is around LEM bulb. The noise control for Lightwave Spherical Light is in QUALITY TAB - Luminosity Threshold and minimum value for that should be 100/0:

I don't know if I understand correctly: what do you mean by do not illuminate with bulb? I was thinking to put a IES light in a lamp...

EDIT: ---> And another question: why Luminosity Threshold and Blurring Threshold MAX are 0 (zero)? Doesn't have to be something like 100/x00 instead? go it, stupid question actually, with max set to 0 it calculates fixed value you put in min, of course.

[Janusz Biela]

Is just do not try illuminate interiors with small light LEM sources. It affects bad photons which is normal in Final Gathering (this will change in K3) Better is just create LEM with soft light max 300% Luminosity (You need reflection effect ) and rapid it with Physical Light.

Some values doesn`t need to be setup with both parameters (min/max).
For example when you render in QMC (UnCache mode) you need to setup only min rays in FG Tab and for example 500/0 is correct value for medium quality, For high quality 1000/0 etc. . Also for blur for example can be only minimum rays: 500/0 or luminosity Threshold 100/0 (Spherical Light).

If you want render in Path Tracing then also min rays you keep high (100 fast prev, 500 good quality, 1000 better quality), second parameter max ray can be zero.
Remember also if you use Path Tracing only Min Ray and Max Rays are activated, rest options in Final Gathering Tab doesn`t work. These all will be "hidden" in K3. Only renders buttons (with ready pre-settings)