how to optimmize yafray rendering

now yesterday I played a littlbe bit around with photons and dispersion /refraction. this is what came out:

Now what I want to know is: is there any possibility to get such a picture with accurate physics on a 1.5 GHz computer without having to render it more than 6 hours :D?

(ther is only one lightsource on it, as well as only a single photon light. with about 150.000 photons. Method is “Full” and Qualita is “Best”. “Cache” & Photons" is completly turned of. thus the only photon emitting thing in my scene is the photon light. I also had turned on Auto AA. and two objects in my scene a “box” and the glas prisma in front of the camera. But thats it - doesnt look very difficult to render for me… (I mean at least it doesn`t explain why it took me 6h to render))

Hi yeus!

This is a trap ! :O)
I know it – once I was also catched :O))

The thing is: Photon lights does not emit visible light in the normal way.

Simply add a spot or area light at the same position and pointing to the same direction as the photon light. Keep the
opening angle of the pohton light as small as possible. Just for checking select the photon light and Press ALT-KEYPAD0
to use it as a camera view in 3DView to check what is covered by the phtons and what not.

Increase Power of both lights to about 5 – just as a start value.

Increase CDEPTH and DEPTH to 20 (which will decrease rendering speed – but you wanted a “physically correct” rendering – or at least the illusion of it :wink: .
Indrease DEPTH of the photon lamp to 20.

In the mirror transparency panel of the material of the objects set PWr to 0.1 and Samples to at least 2ß.

Set DS in respect to the size of the objects – not that light is completly swallowed on the way through the object.

And: Keep the whole scene SMALL! Yafray dont like to throw photons over a great football field ! :slight_smile:

And after that it is still a lot of fiddeling with the setiings until it looks realistic.

I am still at the very beginning of this type of renderings !

Have a nice weekend!

Simple formula - Caustics = Slow.

Also phsicaly accurate lighting is something else. Its not what most renderes do at all. Thing is you probably don’t care about the physisc if it “looks” real.


shooting photons in combined with raytracing comes pretty close to reality. I don`t think there is a better method out there, which is mire accurate. although it is very slow ;).

In order to be unbaised/physically accurate there are a few modifications that usally need to be made with the base methods. With a corosponding slow down.

But thats really my point. Accurate enought is what you want…And genrally a bit unphysical so that parameters can be fiddled to get the desired effect.