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View Full Version : Getting shadows around nostrils..??


gizmo1990
11-29-2003, 12:31 AM
Argh I just can't seem to get this right!!

I'm trying to light a simple scene with a human head from the front. I've got a single spotlight above and to the front pointing towards the model and Im using a shadow map on the spot.

So far so simple... the problem is I can't seem to get the shadows around the nostrils to work properly!!?? By this I mean the holes themselves should be black but I don't want a heavy shadow going on to the upper lip of the nose itself. No matter how much I play with the map size and fuzziness I either get the nostrils in shadow but with a big shadow of the nose too OR if I strip the fuzziness right down I get no nose shadow but the inside of the nostrils is illuminated?? This part I really don't get, surely if I dont have any fuzziness then at the very least because the rear inside wall of the nostril is obscured by the outside of the nostril it should be IN shadow and dark??

Maybe Im just not seeing something completely obvious but if anybody could put me staight on this I really appreciate it!

Jim.

pixelranger
11-29-2003, 01:20 AM
If the case with the hi res shadow map is that you get an unwanted shadow from the nose that goes down on his/her lips try to move the light down and maybe abit to the side (to get a nicer illumination of the object).


(unrelatet to the nose case: also maybe add a light that illuminates the object from behind so you get a illuminated silhuette)

SplineGod
11-29-2003, 02:13 AM
If youre having shadow map problems trying decreasing the cone angle and/or increase the shadow map size.

CourtJester
11-30-2003, 05:06 AM
argh, the trials and tribulations of shadow maps...

I'd solve the nostrils issue by surfacing means.... texture the interior of the nose to darken on the way in. Then you could have the nose shadow be as soft, sharp or nonexistent as you like.

Other than that, if you have enough shadow resolution to darken the nostrils but have the shadow on the lip, address it the way you would in the real world -- camera angle, lighting angle.

Or, if it's a still and render time isn't an issue, try an area light with raytracing.

SplineGod
11-30-2003, 05:32 AM
We used to put negative lights in the mouths of characters sometimes to reduce the effect of lights that had shadows turned off. :)

Brett H.
11-30-2003, 04:49 PM
Originally posted by SplineGod
We used to put negative lights in the mouths of characters sometimes to reduce the effect of lights that had shadows turned off. :)
I've actually done that with noses, mouths, and navels. Works pretty nicely.

Brett

gizmo1990
11-30-2003, 06:55 PM
Thanks guys. :bowdown:

The surfacing and neg lights suggestions sound like they'll do the trick, why didnt I think of that!? :blush:

SplineGod
11-30-2003, 09:46 PM
Originally posted by gizmo1990
Thanks guys. :bowdown:

The surfacing and neg lights suggestions sound like they'll do the trick, why didnt I think of that!? :blush:
Would YOU want a negative light up your nose? :hmm:

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