10 replies to this topic

[illd]

Hi Forum,

I wish there was a way to upload scenefiles or screenshots here - I was searching for about 30 min...so I have to explain my issue:

When using Area shadows in Cinema 4D they are looking really ugly (aliased?) on geometry that is close to intersect (like pages on a book). It seems this effect is dependent on the angle of the camera. I tried Increasing antialiasing,shadow samples and shadow accuracy neither didn´t help on the Area shadows.

By using Shadow maps it is looking better, but is far from perfect. Is there a workaround?

Here is a Picture and the scenfile:

http://dl.dropbox.co...Area Shadow.jpg
http://dl.dropbox.co...Problem.c4d.zip

Edited by illd, 21 April 2012 - 06:39 PM.

[Crasto]

Are they grainy/noisey? I had this problem recently overcome it by changing Ray Depth and Shadow Depth from 15 to 6 and the ShadowMin Samples to 15 and Max Samples 75, Accuracy 100, Transparency Checked.

[Mylenium]

Increase the samples on the lights, not in the general rendering settings.

Mylenium

[vozzz]

you can host images on imgur.com and then link them to here.

[illd]

Are they grainy/noisey? I had this problem recently overcome it by changing Ray Depth and Shadow Depth from 15 to 6 and the ShadowMin Samples to 15 and Max Samples 75, Accuracy 100, Transparency Checked.

Damn - it didnt help. No difference at all...

Increase the samples on the lights, not in the general rendering settings.

Mylenium

I doubled it form 40 to 80 samples - no visual difference.


As a workaround I excluded the Pages from the area shadows and relight them instead with a little GI. It s not perfect but so I can keep those nicer area shadows for the environment and the pages are now lit with a soft gi.
It seems the only solution right now...

[Mylenium]

Have you experimented with the ray threshold in teh render settings' options section?

Mylenium

[illd]

Have you experimented with the ray threshold in teh render settings' options section?

Mylenium

Good Idea - but it made no difference if I had choosen 0,50 or 100 percent.
If I set the shadowdepth to 0 the bad effect is gonne - but at 1it is fully back.

[illd]

I just uploaded a picture describing the Problem and a scenfile:


http://dl.dropbox.co...Area Shadow.jpg
http://dl.dropbox.co...Problem.c4d.zip

[tarzan_jesus]

You sir, have an anti-aliasing problem.
When ever you have thin strips of high contrast that start stepping and blending together this should be the first place to look.

bump up the min level to :2x2
and the max level to: 8x8
and then lower the threshold to around 2.5 - 5%

Prepare for longer render times.
I went from 1:23 to 2:24
Now as a proper sell, dropping the exact same scene into the physical renderer produces a render time of 0:08

One thing you may want to do is ditch sinc as the AA method and choose a filter that is faster / has less sharpening...unless it is really needed.

Edited by tarzan_jesus, 24 April 2012 - 02:44 PM.

[illd]

You sir, have an anti-aliasing problem.
When ever you have thin strips of high contrast that start stepping and blending together this should be the first place to look.

bump up the min level to :2x2
and the max level to: 8x8
and then lower the threshold to around 2.5 - 5%

Prepare for longer render times.
I went from 1:23 to 2:24
Now as a proper sell, dropping the exact same scene into the physical renderer produces a render time of 0:08

One thing you may want to do is ditch sinc as the AA method and choose a filter that is faster / has less sharpening...unless it is really needed.

Ok - sounds good - I´ll give it a try. To be honest I only tried the AA methods sinc and still frame, but did never touch the threshhold.
Is there a way to force the extra AA only on the problematic layers via a tag or so? I thoiught I saw that some where but maybee I mix it up with the motionblur tag...

[destro]

Ok - sounds good - I´ll give it a try. To be honest I only tried the AA methods sinc and still frame, but did never touch the threshhold.
Is there a way to force the extra AA only on the problematic layers via a tag or so? I thoiught I saw that some where but maybee I mix it up with the motionblur tag...

It's an option in the compositing tag.