2sided material blotchiness

[thanulee]

Hi, even with very high settings my GI seems to be really blotchy when light passes through a 2sided material. Any ideas why? thanx

[Scott Schroeder]

Please post a screencap of your issue as well as your material settings and render settings. It is much easier to diagnose this with those.

[thanulee]

I cannot provide screenshot of the project im working atm. Imagine though, there is this "creature" which is supposed to be glowy and illuminate a dark scene. So i place a spherical light inside it and I apply a 2sided material. My settings are basic vray setup with irradiance/lightcache combo with really high settings in both of em. For example: HSph, subdivs: 80 / Interpolation samples: 50 and rest global settings are like high to have 0 noise, 0 alising etc. Interpolation samples actually controls how samples blend to avoid blotchiness. Still though the render is not 100% smooth (50 is really high value and it will probably start losing sharp details if i increase it more), and i can imagine that when i ll animate this i ll have tones of issues from what i can tell by seeing the still frame.

So any suggestions? Maybe i should go for another approach if i want a glowy creature? Vraylight is not good solution as material imo in this case, it will cause flickering/noise problems plus doesnt provide as good result as the 2sided, color is a bit flat. Or maybe im missing something in the 2sided material which can improve how GI passes through it?

Thank u very much!

[Scott Schroeder]

What is your current material set up looking like?

 

Have you tried using a vray light and setting it to use the mesh of your creature as the light shape? What about using a basic Vray material and using some translucency to spread that inner glowing light around the mesh? Have you tried using the FastSSS2 material? It sounds like your 2sided material isn't giving a great result either so you might want to revisit your vray light material.

 

Either way, you'll probably need to combine a material and an actual light source to get this to work. Using a vray light material to illuminate can crush your render time and give you a lousy result as you probably have seen. But the material by itself can give the illusion of the glowing creature while an actual light does the scene lighting.

 

Work on getting some screencaps.

[thanulee]

Its just a basic vray material as coat on a vray2sided with 50% lets say translucency (a medium grey color). Inside of the creature i have a spherical light (samples of light doesnt fix that blotchiness i described also). U suggest that i should go with fastSSS2 with the light inside the model as well? Ya vray light material i think is out of question. thanx!