Sucky shadows using only-shadow spot

Support Basics & Interface
1

Hi there… I haven’t been able to find earlier only-shadow-spot-trouble-postings about this problem, so here goes :-?

I’ve set up an only-shadow spot, but it creates weird sort-of-shadows on the ground ( in this case, the desert ). I made a screenshot which pretty much covers the setup, including other lights, spotlight-setup, and rendered image. You’re looking through the spot, btw.

http://orion.luon.net/~roderik/documents/blender/pictures/suckyshadows.jpg
(The image is 376 kB, presumably 1280x1024.)

What causes these dark squares at the palmtree - and how do I scare them away ? :<

Thanks in advance :slight_smile:

2

try decreasing the Bias value.

Martin

3

i tried… but it only made it worse! (that’s actually how i came upon the problem; the tree’s shadow was also acting a little bit weird in the sense that close to the stem, the shadow wasn’t even visible, and at the end it was the most … a blending shadow, as it were)

increasing the bias worked fine, but then, the problem with the shadow was there again… argh!

thanks anyway :slight_smile:

4

Yup, it’s a problem.

The best thing to do is probably scream at your computer, run around shouting and fill in a bug report form at blender.org.

Until this gets fixed the only thing I know to do is to try and work around the problem, hide the shadows at the base somehow…

…or something.

:frowning: :frowning:

5

Increase your shadow buffer size.

6

I cannot see you image, but I guess you get shadows where they should not be, maybe a ring of shadow outher of the spot cone?

If this is the case rise SpotBl and keep Samples, Soft and Bias low.

Stefano

7

Superdan: even with the shadow buffer size at 5120, nothing changes…

Stefano: I know… somehow the server went down, and since it’s stationed at a university, it will probably not be up till tomorrow. What I got was that some faces of the subsurfed plane (the desert) got dark - without anything casting shadows on it, and you could easily identify the faces by the seams of the dark areas.

I set the subdivision to 2 instead of 1, and the problem was no more… :smiley:

8

In general, I would not advice using the shadow-only mode at all. For direct light in my scenes, i ALWAYS use normal spots. If in doubt, just use a very wide spot angle and a big (8192x8192) shadowbuffer.

9

Try changing the shadow clipping (“ClipSta” & “ClipEnd.”)

Here’s what I mean:
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