Indigo Renderer Forum

Hi!

I would like how to do a hard shadow (and not soft shadow) with the sun?

thanks
johan

which versions do you use?

Well since the atmosphere in Indigo is phisically based its gonna be hard, because the atmosphere scatters light a bit Anyone knows how if its possible? Perfectly sharp shadows are impossible in the real world and since Indigo is a mathematical replica of the real world in terms of lighting it might be impossible in it too...

Hard shadows happen all the time. Take a Sunny 16 day. As long as my shadow isn't much longer than I am tall, it will appear to be nice and sharp. There's a limit to what our eye's can see.

Todo it in indigo I believe that you set up a sun with a low gain. When I experimented with linear tonemapping, a sungain of 0.005 and a linear_gain of 5000000 gave me very sharp shadows. A sungain of 5000000 and a linear of 1.0 gave me almost no shadows.

I hope that helps.


dogfin -

Yes, set the sky gain to a very low value. Setting the sky turbidity low helps, also. Something like 1.7 should be fine.

And dogfin, this is my first year in Film and Animation, so now I actually know what sunny 16 means!

/Yays for me.

ok, thanks but I have yet a soft shadow
but how to use sunny 16?
where to add the code for its good hard (or burn) shadow with sunny16?

thanks
johan

I use Blender 2.42a and Indigo 06t2

Oh sorry johanjohan, didn't mean to confuse you. Sunny 16 is a photography term. Its basically a summers day in brighness for us non-photography people. (Actually, a summers day may be a bit brighter than sunny16).

Anyway, keep lowering you're sky_gain. 0.005 is a good starting point, just keep lowering it. Don't be surprized by insane numbers like 0.000001. See if that works. (I'd test this myself, but all my cpu power and ram are in use). Later.


dogfin -

yess its cool its now with sharp shadow
for me its with :

<linear>
<scale>5000000</scale>
</linear>

<turbidity>2.000000</turbidity>
<sky_gain>0.0000000000000000000000000001</sky_gain>

but its strange because there are not the "background" sky gradient, its black..

thanks
johan