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It's been quiet indeed, for a long time, saddening. I'll be there too.

Ompf beers of a feather!

I mostly agree with you, vchizhov . My understanding is that the delta function is an ad-hoc construct, often defined as \int_{-\infty}^\infty f(x) \delta(x - x_0) \, dx = f(x_0) Note that the above is not a valid Lebesgue integral. A more rigorous, Lebesgue-compatible definition is as a measure: \i...

Point and directional light sources are not physical and are commonly defined via delta functions/distributions. For a delta directional light, you take the solid angle version of the rendering integration (which is what you have above) and replace L_i by a an angular delta function, which makes the...

In Veach's framework the measurement contribution of a path is always the same and it includes all cosines and inverse squared distances along the entire path. But a given path can be sampled in many different ways, i.e. via different techniques. The pdfs of some techniques will include some cosines...

Everything seems to be back to normal, thanks a lot Jacco!

I now always get a message "No route found for "GET /ompf2/viewtopic.php" when posting in the forum or when opening a topic from the RSS feed. Any ideas?

I was initially excited by the title of the paper but I soon found a deal-breaker. With primary-/path-space path guiding, the dimensionality of the ideal cache is infinite. But the radiance field in the scene in world space is only a 4D or max 5D function (surface/volume + direction). Prior path gui...

TL;DR: If a ray randomly hits a light source, you should not be multiplying by the cosine as it's importance sampled and cancels out. In Veach's integral formulation of light transport it's all crystal clear. The radiance emission at every point on a diffuse light source is uniform (i.e. the same in...

Will investigate. Hints appreciated ;-) Yeah, doesn't look correct. The most likely reason is that the MIS weights corresponding to the different techniques for constructing a path don't sum up to one. This in turn is probably due to incorrect/inconsistent path pdf computation. What has helped me g...

The problem is that the probability you use for choosing a light source is itself a random variable. If you write out the estimator you're building with your sampling techniques, its expected value won't be what you want. To get an unbiased estimator, you'll need to divide not by that random probabi...