Please correct me if I'm wrong. Does Le(p,w0) here means the irradiance emitted from point p on surface when not considering light?
(eg. When not considering light, we can consider surface point p as a point light source if the surface is shining. If the surface does not shine, then Le(p, w0) can be considered as 0)

@Nina. It is radiance emitted from point p in direction w_o. (But this is very much "considering light"! I think you mean when not considering reflected light.)

lucida

Why don't we also need to weight the emitted light from point p by a cosine? The light emitted from p does not necessary hit the lens at an angle perpendicular to the lens' surface.

kapalani

I think its because we're trying to compute the amount of output radiance from point p in the direction wo. The Le term we are considering is already giving us the radiance along wo, so there's no need to multiply by cosine.

Please correct me if I'm wrong. Does Le(p,w0) here means the irradiance emitted from point p on surface when not considering light? (eg. When not considering light, we can consider surface point p as a point light source if the surface is shining. If the surface does not shine, then Le(p, w0) can be considered as 0)

Thanks.

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I think slide 36 can answer this question.

@Nina. It is

radianceemitted from point`p`

in direction`w_o`

. (But this is very much "considering light"! I think you mean when not considering reflected light.)Why don't we also need to weight the emitted light from point p by a cosine? The light emitted from p does not necessary hit the lens at an angle perpendicular to the lens' surface.

I think its because we're trying to compute the amount of output radiance from point p

in the direction wo. The Le term we are considering is already giving us the radiance along wo, so there's no need to multiply by cosine.