Indigo Renderer Forum

Sorry guys, I spotted it this morning when doing another test render for a tutorial.
Simply, the Sun has edges. I remember that this issue has been reported before, but I don't remember if it hadbeen fixed for the previous versions.
Btw, here are the images

Sorry to say that but it's not a bug it's just an issue that pops up when using any sharpening filter.
Use a Gauss filter or better use AD instead which is more real anyway.





take care
psor

Or simply set your Super Sampling to 2 or higher

This won't help cause it's caused by downsampling and using Mitchell-Netravali as filter.


On the technical side, it's caused by float rounding errors and those lead to negative values
which are then clamped to zero (black). To lower the effect you can increase the bluring and
decrease the ringing. To avoid it, use a gauss filter instead and use a sharpening filter in post.


Anyway, using apperture defraction is much closer to reality and so just leave the filter as
it is and don't ya think to much about it.






take care
psor

I had the same problem with the lights in this scene. Where I turned the super sampling to 2 it fixed the issue, though.

The supersample factor is already set to 2 and I'd strongly avoid to raise it, most of all because of the RAM consumption: it would work for a test scene like this, but could be a problem whith higher resolution renders.

BTW this stuff about sharpening and blurring and filters and stuff is way too complex for an average user, and - you have to agree with me - is quite tricky.
I suggest that Ono works a little more to find a way to eliminate the problem. Having the sun rendered correctly is a right for all.

Sorry Psor: I have to think about it. Perfectionist.

I've tried to render a scene myself. And ya, I've to say this has to be a bug. In the past this
scene was rendering fine, without the "shading" of the sun. And have a look the sun is able
to beam ... so beam me up Scotty!




click to enlarge




Nik, you really have to take a look at this. Mine is rendered with v2.2.7. I've rendered it with
supersampling set to 2 too, but the rendering above it's set to 1 to double check. I've tried
all filters and settings too, no change. The scene is attached to this post.









take care
psor

I lol'd.

I've done a similar scene test, Super Sampling set to 2, there's any edges on the sun but a strange shape (square) on the wall.
SkIndigo 2.2.3 and Indigo 2.2.1

psor wrote:I've tried to render a scene myself. And ya, I've to say this has to be a bug. In the past this
scene was rendering fine, without the "shading" of the sun. And have a look the sun is able
to beam ... so beam me up Scotty!

Hi Psor,
I think the problem with your model is that the sun is too close to the horizon, and the sky model is freaking out.

As a general answer to the dark edge around the sun, I would recommend using aperture diffraction, which should mean that the edge isn't visible.

mr_jo wrote:I've done a similar scene test, Super Sampling set to 2, there's any edges on the sun but a strange shape (square) on the wall.
SkIndigo 2.2.3 and Indigo 2.2.1

I ve already had that.
it is because your exposure is too high.
try reducing the sun power and increasaing the sky power, you will get almost the same result, without the square aperture.

OnoSendai wrote:As a general answer to the dark edge around the sun, I would recommend using aperture diffraction, which should mean that the edge isn't visible.

If you take a look to the top post you will see that the second image has aperture ON and still shows dark edges.
I also confirm mr_jo issue about "rectangular" diffraction even with circular shape enabled.

BTW I think you should find the problem and solve it, for it is often counter-productive to activate the diffraction while rendering, since diffraction uses loads of RAM so Indigo would probably crash... Activating diffraction doesn't SOLVE the problem, though: it is only a workaround. Maxwell renders the sun just fine, Fryrender either: why can't Indigo do just the same? I think Indigo deserves it

Pibuz wrote:

OnoSendai wrote:BTW I think you should find the problem and solve it, for it is often counter-productive to activate the diffraction while rendering, since diffraction uses loads of RAM so Indigo would probably crash... Activating diffraction doesn't SOLVE the problem, though: it is only a workaround.

I think we're talking about physical diffraction, not the PostProcess Filter my friend
No Extra RAM cost and physical correct, a feature I would recommend to turn on always for final renders!!

Also check out your exported igs file, maybe your exporter just don't export the circular Aperture shape... mybe skindigo is the evil her...

Hi ZomB!
SkIndigo actually supports circular aperture..

ZomB wrote: I think we're talking about physical diffraction, not the PostProcess Filter my friend
No Extra RAM cost and physical correct, a feature I would recommend to turn on always for final renders!!

Can you make this clearer? I don't get you completely, sorry
There is a way to have aperture on without using the post-process filter?