This is a very interesting slide that I think really highlights the approximation techniques we use when it is impossible or infeasible to model the real world to the optimal granularity. Obviously we won't have to worry about the pot's lighting being incorrect if the pot's mesh accounts for all the little bumps and scratches at the bottom. However, that would simply be way too complex of a model. Instead, we use a flat surface and save a lot of vertices, edges, faces, etc. by approximating the reflections using a mathematical, simulated surface texture.
srikartalluri
This is really interesting as many elements in renders have innate directionality, that is not captured with isotropic reflections. In addition to the pan in the previous slide, we also see reflective objects such as screws or nails having an innate directionality. Really any brushed metal will exhibit this behavior. However, I am curious how this might work for materials that have multiple brushes (such as a metal that is brushed in the x direction and then again in the y direction that leads to a cross hair pattern)?
maldenz
In rendering, the difference between isotropic and anisotropic reflection is crucial for creating realistic materials. One notable example is in the rendering of hair and fur, which demonstrates a very distinctive type of anisotropic behavior. Hair and fur are made up of many individual strands, each with its own orientation. These strands tend to reflect light in a way that's heavily dependent on the angle of incidence and the viewing direction, leading to effects such as specular highlights, anisotropic shading, and translucency.
muuncakez
@maldenz I actually watched this video a bit ago about how Disney as evolved their process to animate hair: https://www.youtube.com/watch?v=cvTchBdrqdw
it's a more surface level discussion focused around the animating tricks (shape, flow, etc.) but touches base with some rendering engines used to animate hair and gives good examples of their development and usage. With the goal being to make the hair realistic, but rather, make it believable.
ttalati
So, if I am understanding correctly, in anisotropic materials the surface normals along a row/column are all the same and they differ as we shift row wise or column wise, which gives the appearance of similar light reflection along a row/column. On the other hand, in an isotropic surface our surface normals are more scattered allowing light to also be reflected in a scattered manner and being more diffused?
This is a very interesting slide that I think really highlights the approximation techniques we use when it is impossible or infeasible to model the real world to the optimal granularity. Obviously we won't have to worry about the pot's lighting being incorrect if the pot's mesh accounts for all the little bumps and scratches at the bottom. However, that would simply be way too complex of a model. Instead, we use a flat surface and save a lot of vertices, edges, faces, etc. by approximating the reflections using a mathematical, simulated surface texture.
This is really interesting as many elements in renders have innate directionality, that is not captured with isotropic reflections. In addition to the pan in the previous slide, we also see reflective objects such as screws or nails having an innate directionality. Really any brushed metal will exhibit this behavior. However, I am curious how this might work for materials that have multiple brushes (such as a metal that is brushed in the x direction and then again in the y direction that leads to a cross hair pattern)?
In rendering, the difference between isotropic and anisotropic reflection is crucial for creating realistic materials. One notable example is in the rendering of hair and fur, which demonstrates a very distinctive type of anisotropic behavior. Hair and fur are made up of many individual strands, each with its own orientation. These strands tend to reflect light in a way that's heavily dependent on the angle of incidence and the viewing direction, leading to effects such as specular highlights, anisotropic shading, and translucency.
@maldenz I actually watched this video a bit ago about how Disney as evolved their process to animate hair: https://www.youtube.com/watch?v=cvTchBdrqdw it's a more surface level discussion focused around the animating tricks (shape, flow, etc.) but touches base with some rendering engines used to animate hair and gives good examples of their development and usage. With the goal being to make the hair realistic, but rather, make it believable.
So, if I am understanding correctly, in anisotropic materials the surface normals along a row/column are all the same and they differ as we shift row wise or column wise, which gives the appearance of similar light reflection along a row/column. On the other hand, in an isotropic surface our surface normals are more scattered allowing light to also be reflected in a scattered manner and being more diffused?