rendering mosquito nets

[flipside]

Hi,

I'm trying to create a material for a mosquito net as in the following picture:



For now the best results come frome a simple white material with a light grey refraction color. But the main problem is that when you have two layers of the net on top of each other, it should be almost non transparant and become very white. But with my material, these parts get darker because less light can pass through.

Anyone ever tried to render such a fabric or something similar? I'm wondering what material properties are really important to get these very white folds etc.

Any help or some tips would be much appreciated.

regards,

flipside

[suurland]

Try with a standard map and set the transparency to additive.

/Thomas

[flipside]

Hi thomas,

It does indeed what I want, until I turn on GI... Then it gets really slow and the net looks completely bright white. Tomorrow I will experiment a bit more with this.

More tips are welcome

thanks,

flipside

[freak]

i think u should use something call sub-surface scattering...i am not sure is this right or not tho...or i think translucency MIGHT(i doubt it) work......or maybe u can create a frosted glass mtl, then just make the refract glossyness to 9.9, then put a texture map...or something like that, it might work.........

i think if u got a good model...even if the mtl is not 100% right......it should still look alright........

[samuel_bubat]

I would start with a falloff map in the opacity slot for the white folds.

[olitech]

....also slap your fabric texture into the opacity/refract slot...use as one of the falloff channels if u want...don't think you need to go as far as translucency sss

[flipside]

Thanks all!

First I tried with a vraymtl with a falloff map in the refraction slot. I tweaked the curve of the falloff a bit. The problem here is that the parts of the cloth that are not or partially transparant (the sides of the falloff) look dark on the inside of the cloth. Result:



I also tried with a standard material and a falloff map in the opacity slot and the transparancy type set to additive. This is difficult to tweak, and also the parts that get white are generating light as if it is a self illumated material. Probabely I can fix this with a vraymtlwrapper. It also looks a bit like smoke from a cigarette. I wonder if I can not decrease the effect of the additive transparancy a bit?


I don't want to use translucency because it takes ages to render. Also I have to give my cloth a thickness to get a translucency effect because translucency is all anout transportation of light inside an objects material.

Any more tips or tricks (or comments on these two examples)?

thanks,

flipside

[losbellos]

hmmm, well, the material is originally not transparent. There is some space between the line of the textil and that is makes it transparent. Maybe you could go on this way. Either with some opacity mapping or maybe some very tricky displacement, water level or something (which will cut out) dont remember exactly

there is one more way, to play with the glossyness. once I was able to do a good looking transparent silk with transparency and glossyness. Make the refraction to 1.01 or something but not 1

[flipside]

I already tried with a map with little squares to make it look like a cloth with very small holes. This doesn't work well because the holes are so small that everything gets blended into one color imo.

Can you show an example of your cloth losbellos? I always used ior=1.0 in my tests. Why would you use 1.01?

I couldn't resist and started playing with refraction glossiness but it didn't work out well, it had the same problem that parts that looked white on the outside look dark on the inside. It also takes ages to render. When I turn on translucency as well, it gets really weird and I can't get it right.

So I went back the start (opacity on std max material and additive transparancy). I used the map with little holes as a bump map also, and although you don't notice it very hard, if you see it without the bump there is a significant difference.

But I'm working on it so long now that I don't have good judgement anymore about the look if it's real or not. Here's a small animation:

http://users.pandora.be/stor1/vray/cloth_anim_1000.avi

it's 550kb or something

The weird thing is that it doesn't cast GI shadows at all. I already deactivated 'send GI' in the vraymtlwrapper, but thi doesn't help much. If I lower the recieve GI then the material simply gets more transparant, nothing more.

Ok tell me what you think about it!

Thanks,

flipside

[losbellos]

now I see your problem mmm, I'll try

[flipside]

Hi losbellos,

Not sure what your talking about...

Do you mean color blending?

regards,

flipside

[losbellos]

I mean bending, I see now what is your problem, and there is an other one if direct light goes on the net, the shadows will be too hard.

[losbellos]

So far this is the best result, but I got an other idea, its a two step process.

[flipside]

Can you printscreen the settings for that material?

[losbellos]

please wait, I have a better solution... But it takes a little time ti figure out the right values.