A study on glass - Blender/Cycles.
I have always found glass to be one of the most attractive things in CGI and real life, but we all know that there are some limitations regarding the creation of glass specially on non-bidirectional render engines, which is the case of Cycles.
Bidirectional path tracing basically works by generating a subpath starting from the light source and a second subpath starting from the camera, instead of just the path from the camera.
By calculating both of these paths, some key aspects of glass can be realistically simulated, such as Dispersion, Refraction and Caustics.
After collecting and combining information from texts and videos, I wanted to create my own optimal glass shader in Cycles to achieve a slightly fast material to render and customize, and realistic at the same time.
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Key knowledge and resources used for this study comes specially from Gleb Alexandrov, Vilem Duha, CG Cookie, Syncretic 3D, and the Stanford University.
I have always found glass to be one of the most attractive things in CGI and real life, but we all know that there are some limitations regarding the creation of glass specially on non-bidirectional render engines, which is the case of Cycles.
Bidirectional path tracing basically works by generating a subpath starting from the light source and a second subpath starting from the camera, instead of just the path from the camera.
By calculating both of these paths, some key aspects of glass can be realistically simulated, such as Dispersion, Refraction and Caustics.
After collecting and combining information from texts and videos, I wanted to create my own optimal glass shader in Cycles to achieve a slightly fast material to render and customize, and realistic at the same time.
-
Key knowledge and resources used for this study comes specially from Gleb Alexandrov, Vilem Duha, CG Cookie, Syncretic 3D, and the Stanford University.
Most of the renders are 6K to 4K minimum, 2000 to 5000 samples with 64 depth bounces for all channels.
Showcasing this amount of detail would take too much time on my computer so I chose to use RaysRender, they work just how it should, straight to the point.
Showcasing this amount of detail would take too much time on my computer so I chose to use RaysRender, they work just how it should, straight to the point.
Dispersion: dispersion basically works from the changes in the speed of light caused by the IOR (Index of refraction) between air (1.0003) and glass (1.450).
When light paths travels through refractive objects, it carries all the colors with itself, depending on the IOR of such object, refraction affects the speed of independent light rays from certain colors.
This can be simulated inside of Cycles by adding and subtracting the color channels.
When light paths travels through refractive objects, it carries all the colors with itself, depending on the IOR of such object, refraction affects the speed of independent light rays from certain colors.
This can be simulated inside of Cycles by adding and subtracting the color channels.
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Caustics:
Light Paths:
Comparison between my shader and Cycle's default Glass BSDF:
Clay:
Credits: VizPeople, Vladimir Radetzki and pingo van der brinkloev for some of the 3D models.
This project was very different from the usual, it focus more on the study than the final art/renders, I hope you enjoy.
This project was very different from the usual, it focus more on the study than the final art/renders, I hope you enjoy.
