Dies is cast - and problem with sun

[psychotron]

Hello,
I'm new to blender and indigo too.
I have problem with radiance of sun - render is dark. I try to change energy, distance and position (in Z) of sunlamp in blender but in indigo render is all the same.
I looked to documentation and then try change sky_gain in XML file manually from value 0.005 throught 0.01 to 0.8 and render is still the same - so my render is very dark again.
In export script I choose sunsky and turn off bidirectional button.
What I must do to have nice sunny renders like many others in this forum?

[OnoSendai]

Hi, i think you just want to crank up the image brightness, as opposed to the scene emitter brightness. It's basically a tonemapping/exposure issue.
try setting the burn value to a smaller value, e.g. 0.1
(hopefully that's in the blender exporter, not sure)

[drBouvierLeduc]

As far as I understood, in blender, the distance and energy of the sun don't have any effect in indigo. The only things that matter are its place and its rotation (well, I mean the rotation of the dotted line in blender).

To get a brighter picture, in the exporter settings, try to put higher values in the "PreS" and "PostS" fields, like 2 and 3 for example (or more). I get correct results up to 4.
Also, the higher "sky turbidity", the clearer the sky.

[psychotron]

thank you both
I try yours recommendations and you can see test renders - I must experiment with these parameters a bit more now...
btw what with shadows - I think these shadows are too sharp and dark for glass material.


1. burn=0.1, preS=1.0, postS=1.0



2. burn=0.8, preS=4.0, postS=4.0

[zsouthboy]

RE: shadows looking too sharp:

Two things:

The penumbra (the fuzzy part of a shadow between full shadow and none) is influenced by the distance between the occluding object (the dice) and the receiver of the shadow (the gray plane), and the size and distance of the light casting object.

The sun is quite huge, but to us, it's just a few inches in our vision. Also, by the time rays hit the earth, they're quite parallel to each other.

The shadows you see are correct for the above conditions. If you go place a few dice outside on the pavement at 11, you'll see shadows just like that!



To make the shadows appear "fuzzier", use a meshlight modeled realistically in size and distance. For example, a 4 foot x 2 foot plane shining downward on the dice, from 4-6 feet away.