Timeline for Is there a name for the values of a material at a point?
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
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| Jan 16, 2024 at 20:18 | comment | added | lightxbulb | The it is still a bsdf sample, just one that is only positional $f(x, \cdot, \cdot)$, i.e. it returns a function. The parameters that define the bsdf vary quite a bit depending on the model. | |
| Jan 16, 2024 at 19:56 | comment | added | Kevin Reid | @lightxbulb The concept I am looking for does not include the incoming or outgoing directions; that is, the sample is some representation of the function $f(\omega_o, \omega_i)$, just as sampling textures gives you parameters you can then use in your actual BRDF with your actual ray directions. | |
| Jan 16, 2024 at 19:56 | history | edited | Kevin Reid | CC BY-SA 4.0 | added 75 characters in body |
| Jan 16, 2024 at 19:46 | comment | added | lightxbulb | A sample of the brdf/bsdf? You feed it a position, an outgoing and incident direction and you get a value $f(x, \omega_o, \omega_i)$. Many people mix in Lambert's term into this, i.e. $f(x,\omega_o,\omega_i) |n_x \cdot \omega_i|$, so that would be a sample of the product between the brdf/bsdf and the cosine. This tells you everything you need to know about how much radiance arriving from direction $\omega_i$ is reflected at location $x$ along direction $\omega_o$. | |
| Jan 16, 2024 at 16:20 | history | edited | Kevin Reid | CC BY-SA 4.0 | note on the existence of “maxel”. |
| Dec 1, 2022 at 0:09 | history | edited | Kevin Reid | CC BY-SA 4.0 | added 15 characters in body |
| Nov 30, 2022 at 23:40 | comment | added | Kevin Reid | @NicolBolas I was thinking of normal-mapped surface detail, like cloth or leather might have. Perhaps that is a bad example since it does relate more to the shape than the other things you refer to. I must admit that I'm not greatly familiar with the finer points — I'm a programmer doing this for a hobby, not an artist or professional game developer. That's why I'm asking this question — I want to use accurate and clear terminology. I've changed the list of examples to hopefully be more relevant and uncontentious. | |
| Nov 30, 2022 at 23:33 | history | edited | Kevin Reid | CC BY-SA 4.0 | added 64 characters in body |
| Nov 30, 2022 at 23:22 | comment | added | Nicol Bolas | What if we take issue with your definition of, for example, "material"? Like, generally speaking, I would use the term to refer, not to things like a "normal map", but to the particular elements in the lighting equation that describe the surface (as modeled by said equation). Surfaces have a normal, but it doesn't matter to the "material" if that normal comes from a per-vertex interpolated value or the result of a texture access. "Having a normal" is a material parameter; where the normal comes from is not the business of the material. | |
| Nov 30, 2022 at 21:57 | history | asked | Kevin Reid | CC BY-SA 4.0 |