Physically-correct tool for realistic curtains and cloth fabric
Creating a good curtain material is hard and time consuming: sometimes we want it to let some light through and glow when hit by sunlight, some others we want it just to be translucent and blind direct light. And transparency does seem always off: it' s either too much or it does resemble frosted glass instead of thin fabric. Also, common tricks to let light through do destroy reflections on glossy surfaces
That's because, in reality, fabric involves a lot of interactions with light: threads interwoven do absorb and scatter some rays, while slightly deforming and letting through others. The physics behind light interactions require to carefully craft a system of interconnected curves, fine-tuning each parameter
Advanced Curtain Shader is a faithful modeling of physical light interaction, specifically optimized for curtains, drapes and veils. It is also suitable for other kind of fabrics, such as lace, carpets, blankets and also lamp shades
EASY TO USE
It enables you to craft beautiful curtains and let them interact with light as you want: from glowing, to half-tones light bleeding, to translucency. With the transparency slider not only you control the visibility of objects behind, but also how much light gets through and its nuances of shading. All while keeping reflections on glossy surfaces!
One of the most important aspects in fabric optics, is ambient occlusion: It adds a lot of realism by darkening the edges around creases; only problem with that, is that the latest Nvidia Optix technology doesn't allow the use of the standard ambient occlusion node, leaving you with the only option to render on slower standard mode. In Advanced Curtain Shader, ambient occlusion has been reproduced using only standard nodes, with fresnel and curves: it is Optix ready!