Ceramic material (SSS ? specular ?)

[bioman666]

Hi everyone,

I'm trying to make a decent white ceramic material, and I need it to be accurately modeled since there will be no bump map or texture to hide behind...

So far i've found these recipes :

1. the skindigo ceramic preset (phong with 1.52 IOR, 5000 exponent and some bump map)
2. the "ono recipe" (Phong with .8 diffuse and .04 specular)

but what i'd like to achieve is more like this :

.

The guy seems to use an SSS layer, but i can't figure out a way to do this on Indigo...

Has anyone an idea ?

[bioman666]

and the luxrender wiki talk about a glossy material (phong equivalent ?) that can get rather close to what i'm aiming (see attached : the 100000 exponent, in the lower right corner of the pic), but I only get black shiny material if i turn on specular on a glossy transparent material in indigo...

moreover, i can't get this code (ono recipe) to work :

Code: Select all

<?xml version="1.0" encoding="utf-8"?>
	<scenedata>
		<material>
			<name>ceramic_ono</name>
			<phong>
				<diffuse>0.8 0.8 0.8</diffuse>
				<specular>0.04 0.04 0.04</specular>
				<exponent>5000</exponent>
				<fresnel_scale>1.0</fresnel_scale>
			</phong> 
		</material>
	</scenedata>

[bioman666]

OK so far this is the best i could achieve : it's a blend between two phong materials (one for the diffuse and one for the specular) with a texture to control the blend ratio (as the transparent layer on a ceramic may not be even).

Thanks to Pibuz green car paint material for inspiration...

I'm not that satisfied though, i could use any suggestion, feel free to make any ! To me the reflection is not sharp enough, compared to the Vray material.

<?xml version="1.0" encoding="utf-8"?>
<scenedata>
<material>
<name>metallic_green_matA</name>
<phong>
<diffuse_albedo>
<constant>
<rgb>
<rgb>
0.9961 0.9961 0.9961
</rgb>
<gamma>2.2</gamma>
</rgb>
</constant>
</diffuse_albedo>
<exponent>
<constant>
250000
</constant>
</exponent>
<layer>0</layer>
<fresnel_scale>1</fresnel_scale>
<ior>1.347</ior>
<nk_data></nk_data>
</phong>
</material>

<material>
<name>metallic_green_matB</name>
<phong>
<specular_reflectivity>
<constant>
<rgb>
<rgb>
0.9102 0.9023 0.8633
</rgb>
<gamma>2.2</gamma>
</rgb>
</constant>
</specular_reflectivity>
<exponent>
<constant>
3008
</constant>
</exponent>
<layer>0</layer>
<fresnel_scale>1</fresnel_scale>
<ior>1.5</ior>
<nk_data></nk_data>
</phong>
</material>

<material>
<name>metallic coat_green</name>
<blend>
<texture>
<path>E:/EHTech/Communication/COIFFEURS/PACKED_2_Specular.jpg</path>
<a>0</a>
<b>0.7</b>
<c>0</c>
<uv_set>default</uv_set>
<exponent>2.2</exponent>
</texture>
<a_name>metallic_green_matA</a_name>
<b_name>metallic_green_matB</b_name>
<blend>
<texture>
<texture_index>0</texture_index>
</texture>
</blend>
<step_blend>false</step_blend>
</blend>
</material>

</scenedata>

[bioman666]

This is better (higher exponent in specular phong material) :

[Meelis]

What about exponent 40k-50k for phong with a little displacement for just a slight surface variation.
And sss medium and diffuse transmitter blend with phong material.

[Meelis]

Try that
It's pnong and diff tran blend

[ENSLAVER]

Ceramic materials aren't the easiest to create, unless you have an actual sample to match, clays and glazes vary in colour, translucency, surface texture and glaze thickness to a great extent.

Is it a white glaze? Or a clear glaze on a white clay?

[bioman666]

@ Meelis : thanks, it looks pretty good this way ! I guess SSS was not necessary after all...

@ ENSALVER : the material i want to match is the first posted, it's a VRay material. I have no "real" material to match, so no specific composition to use. But I think it's translucent white glaze, hence the supposed need for SSS.

[ENSLAVER]

@ Meelis : thanks, it looks pretty good this way ! I guess SSS was not necessary after all...

@ ENSALVER : the material i want to match is the first posted, it's a VRay material. I have no "real" material to match, so no specific composition to use. But I think it's translucent white glaze, hence the supposed need for SSS.

Visually the sss is not noticable in that material render, if you want to match it I don't think you need to worry too much about sss unless you are trying to precisely model an extremely thin (<.5mm) ceramic object that will have strong lighting on the edges or backside.

I understand the need for accuracy, but it depends what you're making, if you will never see the sss effect (ie. chunky bathroom tiles) then there is no need to try and render it.

[bioman666]

Yep, that's what i'm thinking too. Yet it might be interresting -- if anyone masters enough this SSS thing -- to use it and upload the material in the library for the upcoming users that will deal with close-up view of ceramic objects...

[ENSLAVER]

Yep, that's what i'm thinking too. Yet it might be interresting -- if anyone masters enough this SSS thing -- to use it and upload the material in the library for the upcoming users that will deal with close-up view of ceramic objects...

Really depends on the object and the type of ceramic it is made from and the glaze. For closeups with a thick transparent glaze I would model it as a separate object, with it's own material. For a thin transparent glaze you could go either way, might get away using just a phong/sss material if the clay is translucent. If the glaze is opaque, then you don't really need a separate model.

[Tramis]

Try that
It's pnong and diff tran blend

Should add this to material database