Talk:Bidirectional reflectance distribution function

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This article could use more context. Who uses this parameter, and for what?--Srleffler 01:50, 14 April 2006 (UTC)[reply]

Expanded a bit. `'mikka (t) 02:31, 14 April 2006 (UTC)[reply]

Measurement of BRDF

The third paragraph should be stricken. The statement that the BRDF function cannot be measured because it represents infinitessimal solid angles is not logical. The statement that BRDF cannot be measured due to the infinitessimality of the input parameters is equivalent to saying that one cannot measure any physical quantity that is not immediately discreet. One can measure the function with the best possible angular resolution, and then (by applying the sampling function) deconvolve the instrument function and reconstruct the original BRDF.

Instruments that measure BRDF are readily used in the optics community to determine the BRDF of the materials used to shield optical systems. Without measurements of BDF, stray light predictions would not be possible. —The preceding unsigned comment was added by 192.91.172.36 (talk) 21:42, 16 March 2007 (UTC).[reply]

I agree with you, corrected article pruthvi 17:39, 18 October 2007 (UTC)[reply]

transmission and scatter functions?

Does anyone have any content on BTDF and BSDF? should we just fold them into this article?58.247.205.172 (talk) 23:00, 19 May 2009 (UTC)[reply]

Irradiance "from a specific direction"?

The following phrase confuses me: "irradiance incident on the surface from direction $\omega _{i}$ ." The definition of irradiance does not mention an incoming direction. What does it mean for irradiance to be incident on the surface "from a certain direction"?--Singularitarian (talk) 10:12, 2 September 2009 (UTC)[reply]

BRDF use in remote sensing

It should also be noted that BRDF has some uses in remote sensing of Earth. Namely, the BRDF derived from the satellite sensor (such as MODIS) data via linear least squares (should one have a suitable model), may be used to calculate black- and white-sky albedos, and also to produce images free from any geometry effects, such as File:MCD43B4.A2009153.mosaic.png.

— Ivan Shmakov (talk) 18:29, 26 January 2010 (UTC)[reply]

Light reflection planar?

In saying that both light rays are parameterized in terms of the azimuth angle, it seems like the reflected ray is not in the plane defined by the normal and the incoming ray. Nowhere is it mentioned that the BRDF is a function that applies to a surface and you pick the direction of incoming light (parameterized into the azimuth and zenith angle) and the point it strikes to plug into the function to get the direction light is reflected from.

At least, that is my understanding after reading the article. If that’s not how it works, the article could use some clarification.

- Adam Gulyas