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Poser - OFFICIAL F.A.Q (Last Updated: 2025 Feb 24 11:54 pm)



Subject: question about shadows in renders


zorares ( ) posted Mon, 20 December 2010 at 6:47 PM · edited Mon, 24 February 2025 at 8:49 PM

file_463126.jpg

Hey, I'm almost finished making this little snowman but I'm having a problem with light seeping through the hat onto his head instead of a shadow.  The hat is a separate object from the snowman and I just can't figure this out.  Using Firefly settings at maximum.  Suggestions?

http://schuetzenpowder.com/sigs.jpg


LaurieA ( ) posted Mon, 20 December 2010 at 7:18 PM · edited Mon, 20 December 2010 at 7:20 PM

Quote - Hey, I'm almost finished making this little snowman but I'm having a problem with light seeping through the hat onto his head instead of a shadow.  The hat is a separate object from the snowman and I just can't figure this out.  Using Firefly settings at maximum.  Suggestions?

Is the hat completely welded?

Sometimes, even if welded, Poser's smoothing will pull the edges apart between verts at a sharply angled crease. Try unchecking the smoothing checkbox in the objects properties. Don't change the smoothing angle, just uncheck the box and see how that does. If that doesn't work, maybe put the hat down a little more to the snowman's head?

Laurie



pjz99 ( ) posted Mon, 20 December 2010 at 7:20 PM

Looks like depth mapped shadow "light gap" to me, I got sick of that kind of thing and went to raytraced a very long time ago and never went back.

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bagginsbill ( ) posted Mon, 20 December 2010 at 7:32 PM · edited Mon, 20 December 2010 at 7:32 PM

The gap is usually shadow min bias - objects within that range do not receive a shadow. Don't ask why it exists - just decrease SMB. If you decrease it, and see little black spots all over the place, you went too far.

And pjz99 makes a great point - raytraced shadows are preferred in most situations.


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jamminwolf ( ) posted Mon, 20 December 2010 at 10:31 PM

Quote - The gap is usually shadow min bias - objects within that range do not receive a shadow. Don't ask why it exists - just decrease SMB. If you decrease it, and see little black spots all over the place, you went too far.

And pjz99 makes a great point - raytraced shadows are preferred in most situations.

That is quite interesting.  I've heard that too little SMB creates spots, but never heard the purpose of it.  Gonna have to see about that in DS, as it does the same thing when using Deep Shadow Map.  Though I never use DSM, as the shadows look too much like garbage/smeared black charcol for nice renders.

 

...wolfie


pjz99 ( ) posted Mon, 20 December 2010 at 10:48 PM

That light leak phenomenon is fundamental to the common way depth mapped shadows are done, not just in Poser but in pretty much all the apps I've seen that do depth mapped shadows.  Combined with their many other quality problems, I'd just never use them for any stillframe render ever ever ever.

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zorares ( ) posted Mon, 20 December 2010 at 10:50 PM

ok, I'm either clueless or an idiot.  You guys are referring to stuff I have no clue of.  OK.  I rendered this in Poser 7 using the firefly render engine.  Where's raytraced?  Where's SMB?  Man, I've been playing with Poser for years and I've missed this completely.  Maybe I am an idiot.

http://schuetzenpowder.com/sigs.jpg


pjz99 ( ) posted Mon, 20 December 2010 at 10:53 PM

Ack don't be like that, nobody said you are stupid!

Look at each light Parameter Dials -> Properties tab and check what kind of shadow the light is set to cast.  If it is set to Depth Mapped (pretty sure it is), you can look at "Min Shadow Bias".  If it's set to Raytraced then something else is making that bright line under the brim of the hat.

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Medzinatar ( ) posted Mon, 20 December 2010 at 11:02 PM

While on subject of lighting, there are two many shadow casting lights in scene.

There are not many circumstances where one sees multiple shadows, and with snowman this would seem unlikely.



jamminwolf ( ) posted Mon, 20 December 2010 at 11:12 PM · edited Mon, 20 December 2010 at 11:16 PM

Quote - Ack don't be like that, nobody said you are stupid!

Look at each light Parameter Dials -> Properties tab and check what kind of shadow the light is set to cast.  If it is set to Depth Mapped (pretty sure it is), you can look at "Min Shadow Bias".  If it's set to Raytraced then something else is making that bright line under the brim of the hat.

Be warned though, with your render settings that high, with raytraced shadows, be prepared for a long render.  There are lots of things to learn, and lots of things to sacrifice in this 3D world lol, trust me.  And no, I too disagree that you're stupid, no one's stupid.  We may be smart in one area but haven't learned a thing in another area, doesn't make anyone stupid :)  

Quote - While on subject of lighting, there are two many shadow casting lights in scene. There are not many circumstances where one sees multiple shadows, and with snowman this would seem unlikely.

 

At least he's got shadows, which is more realistic then even a lot of promos I see hahaha... when looking at a lot of promos, ever wonder where the shadows are and why lights shine under neith the hair or elsewhere unrealistically? snickers

 

...wolfie

 

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zorares ( ) posted Mon, 20 December 2010 at 11:25 PM

file_463130.jpg

and this is why I love Renderosity.  I learn more from you guys than from any book.  

Here is the revised image.  Made a big difference.  Also whitened the snow texture as my kids said that he was dirty looking.  Thanks everyone for the lesson.  

http://schuetzenpowder.com/sigs.jpg


pjz99 ( ) posted Mon, 20 December 2010 at 11:29 PM

If you want to take it a step further, see what happens when you set blur radius for your raytraced shadows (I like it set to 2.0 lately)

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jamminwolf ( ) posted Mon, 20 December 2010 at 11:43 PM · edited Mon, 20 December 2010 at 11:45 PM

Quote - If you want to take it a step further, see what happens when you set blur radius for your raytraced shadows (I like it set to 2.0 lately)

2.0 is nice for ground shadows, but 5.0 is where I set mine when doing close up of, say, a character's face.

zorares, that looks a lot better :)

...wolfie


zorares ( ) posted Tue, 21 December 2010 at 12:16 AM

file_463131.jpg

thanks again.  Here is the snowman with bump maps and blur radius 2.0.  Something new to play with.

http://schuetzenpowder.com/sigs.jpg


Miss Nancy ( ) posted Tue, 21 December 2010 at 12:24 AM

last render is good, but for snow scene, one wants IDL, hdri, one inf lite (sun) IMVHO.  use bill's envdome.



jamminwolf ( ) posted Tue, 21 December 2010 at 4:08 AM · edited Tue, 21 December 2010 at 4:10 AM

file_463133.jpg

Here's something interesting, this has to do with Daz Studio.  It's been a long time mystery to me that shadows were suddenly "cut" in DS when I used raytrace shadows, as well as the ugly lighted line when using deep shadow map.  Always into learning something and experimenting, I went to work and did two sample renders.

1st render (both renders together since we're only allowed one upload... a very small one that is... at Rendo forums) has raytraced shadows set at 4.0, with shadow bias at default settings which is 1.00.  Look at her left shoulder and right arm , where the shirt's gaining in on her skin (and the bottom of the sleeve on her right arm), note the "chopped" shadows.  Then look in side the shirt, at her left arm, note the "light" line, looks like there was a gap in the shirt letting the light in.  Now look at the partial transparent part of the shirt.  Notice how you see a lighted part at the beginning, how shadows start about a half inch from the "belt" of the shirt, and how on the ripple of the shirt, the further away, the further up the shadow?  This was also a mystery to me when using partial transparent settings on clothes.

Now, look at the bikini, specifically on her right side.  Notice the "blahness" that leaves you to thinking with no outline or shadows?  Yes, I used UberEnvironment light for DS, that is, "IBL" in Poser language, which brings in occlusion, but the maximum raytrace distance wasn't high enough for an outside render (less things closed in on the subject of the render).  With the MTD set higher, the occlusion would've been more visable on the bikini edges, but I left it alone.

2nd render, shadow bias set to 0.10, now take note of her left shoulder, right arm, shirt, and bikini again.  Note how much more "outlined" they are and that there's no mysterious "gap light" in her shirt, and no funny ripple shadows.

Figured this would open some eyes here :)  BTW, no funny spots on the lower settings, thankfully.  That's another reason why I don't deal with deep shadow maps ;)

...wolfie


pjz99 ( ) posted Tue, 21 December 2010 at 5:50 AM

Occasionally you see a profoundly stupid default setting in an app - that would be one of those!

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jamminwolf ( ) posted Tue, 21 December 2010 at 5:59 AM · edited Tue, 21 December 2010 at 6:00 AM

Quote - Occasionally you see a profoundly stupid default setting in an app - that would be one of those!

I'll say "Amen" to that, lol!  What makes it embarrassing though, is that I never got that till just now (3 years doing this) lol.

But, well, like I've always said, even the smartest man who's very absorbent can miss the simplest things.

Err... OT here, doesn't Rendo have a spell checker???  What's up with this lousy new forum scripting?  I had to copy/paste everything here to another forum to correct 3 misspelled words lol.  

...wolfie


zorares ( ) posted Tue, 21 December 2010 at 12:08 PM

Whoa!  Very interesting.  Wish I had time to learn both Poser and DS.  Just not enough time in the day.  

http://schuetzenpowder.com/sigs.jpg


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