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Poser - OFFICIAL F.A.Q (Last Updated: 2024 Nov 27 5:12 pm)



Subject: Problems with Lighting and Shadow


baggettbear ( ) posted Fri, 21 January 2005 at 3:43 AM ยท edited Thu, 28 November 2024 at 4:37 AM

file_172825.jpg

This pic is a terrible render, but it highlights a problem I've been having getting shadows to show realistically in outdoor scenes. This image is lit by a single, overhead, infinite light at about 11:30 and slightly in front of the subject. The shadow setting is on, and the subject is set to enable shadows. The light's RGB values are all at 1 and intensity is 200%; the shadow setting is 1.000 and the map size is 512. I'd expect clear, defined shadows on the ground, but all that is visible is a dark area under the subject's left leg. There is no shadow coming from the right leg, nor from the rock at the left. If I add other lights and balance the scene, it looks better, but I still do not get the shadows one would expect.

I'm still pretty new to Poser (Version 5), so perhaps I am overlooking something obvious. But I've scanned this forum and numerous lighting tutorials without digging up any suggestions on how to deal with this situation.

If anyone has any suggestions on how to get more realistic shadows (or can point me to a good tutorial), I would be most grateful.

Thanks.

Mike.


ynsaen ( ) posted Fri, 21 January 2005 at 3:46 AM

increase your shadow map size perhaps, but most certainly remove or reduce the brightness of terrian -- if that's ambient, kill it. If it's alt diffuse, go into greyer shades.

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)


stewer ( ) posted Fri, 21 January 2005 at 4:47 AM

Uncheck "cast shadows" for everything except the gorilla and that rock, that should give you much better shadows. As an alternative, you may try to set the light to raytraced shadows, in which case you need to enable raytracing in the render settings.


operaguy ( ) posted Fri, 21 January 2005 at 10:39 AM

Attached Link: http://www.renderosity.com/messages.ez?Form.ShowMessage=2076958

attached link to a study of shadow map size and effects.

At 200% intensity, which you probably kicked up in desperation for your shadow to appear, you are going to get that harsh yellowing.

You can solve the problem with light at 100% intensity instead.

As stewer said, only cast shadows for the figure and rock, and as ynsaen said, kick the shadow map size way up, to 1000 if you have to. Accept the render time hit.

::::: Opera :::::


lemur01 ( ) posted Fri, 21 January 2005 at 3:08 PM

Crank the shadow size up to about 2000 at least


SamTherapy ( ) posted Fri, 21 January 2005 at 3:42 PM

Nah, 1024 is adequate for shadow sizes. Take a look at some of my gallery images; I'm a shadow freak and never need to go beyond 1024. I tried a few experiments with a single infinite light to simulate sunlight and came to the conclusion that it's not too great. You will be much better placing a lot of low intensity lights in a globe around your scene, to replicate the scattering of light from the atmosphere and objects in the scene. Make sure shadows are OFF for all these lights. For your main light source, ensure shadows are ON. If you're using the P4 renderer, turn shadows OFF for the ground plane/floor. If you're using Firefly it doesn't matter too much. Also, you'll get nice crisp shadows if you enable Ray Tracing.

Coppula eam se non posit acceptera jocularum.

My Store

My Gallery


Nance ( ) posted Fri, 21 January 2005 at 4:42 PM

Haven't stood on this soapbox for a while...

Doubling the Shadow Size does result in a somewhat sharper shadow edge resolution, yet increases the memory demands four-fold for each light. Four times larger =16 times the RAM demands -- and so on.

Why tie up memory unnecessarily, and increase render times, with larger shadowmaps when you can usually do the same for free?

Changing the Zoom level or Scale on the light's ShadowCam, can almost always yield the same change in shadow edge detail, and also permits unlimited scaling for really huge variability in shadow edge feathering, without ANY additional memory demands.

Unless tweaked, the view from each shadowcam, from which the shadowmaps are generated, usually encompasses vast tracts of space in your scene that are not visible in the actual render (such as the entire Ground plane mentioned above), meaning that you are wasting shadowmap pixels, and render time, generating shadows for stuff that will never be seen.

As SamTherapy said above 1024, or certainly no larger than your actual render, is plenty big. For sharper shadow edges, simply zoom the shadowcam view in. For softer, more feathered edges zoom out.

Same shadow map size, same memory usage, same render time.

Who says there aint no such thing as a free lunch?

(with apologies to RAH)


lemur01 ( ) posted Fri, 21 January 2005 at 4:48 PM

Well thanks Nance, ya learn something new every day. :)


nomuse ( ) posted Fri, 21 January 2005 at 5:04 PM

Wow. That's a good trick to keep in mind. Thanks!


ynsaen ( ) posted Fri, 21 January 2005 at 9:15 PM

I utterly hate lights with shadow maps greater than 1024. I almost always use 512 to 768 myself, and if I can go lower, I do. Use of the shadowcams is critical. They are there for a reason -- learning to use them can change a good render into a great one. I once purchased a light set from a store, and that one purchase made me avoid lightsets forever afterward excepting the ones at rdna. The reason? Shadowmaps of 10,000. That's not a typo. Ten Thousand. Commercial lightset. From a well respected merchant, no less! The point, though, is that lighting is NOT as hard as it is often made to seem -- but that there is a great deal that goes into it. Poser's light system is often condemned as bad and such -- but I've found that it can do all the stuff other schemes can do with typically fewer lights and equivalent results at a much lower rendering time. Poser lights are different. I hear them laughed at all the time, but I recall that they are made and designed by someone who might be a lousy biz person, but is a recognized leader in animation and 3d work for film -- bg films. Are they easy -- no. But they do force you to learn good lighting if you want to learn to use them -- and then you can take that into other programs and find yourself doing better work than the ones that simply press the global lighting button. The only thing I ask for in lighting is a point light. IT is the one absent feature in poser's lighting that I feel would make it rock, and would provide the final piece to making incredible lighting setups. But then, I did take stagecraft in school, so I have something at least in the background that lets me understand some of the aspects that are needed. And I'm crazy, too...

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)


operaguy ( ) posted Fri, 21 January 2005 at 10:45 PM ยท edited Fri, 21 January 2005 at 10:49 PM

Okay, this is a teachable moment for me, several experienced shadow people here.

First, I have been really studying the effect of varying
the map size, and am finding the range for my low-light
situation and medium-soft shadows. It's around 480, as in this
frame from an animation I am working on:

But now I'll reveal that I have no idea what
the shadow cam is, or what a point light is.
Just from what's in Nance's post, I am investigating.
Please don't feel any of you have to write an
essay or a DrGeep tutorial, but a few sentences
on each item would send me on my way.

Thank you from a shadow worshiper.

::::: Opera :::::

Message edited on: 01/21/2005 22:49


ynsaen ( ) posted Fri, 21 January 2005 at 11:40 PM

Every shadow casting (depth) light in a scene has a shadow camera. They show up in your camera drop down after poser calcs out the shadow maps (like after you do a test render). Select the camera from the drop down and you get this really funky looking view of your scene. Using the dials, you then zoom and point that camera in so that the ares that are supposed to be shadowed are visible in it. it's a "trick" because you have to know to look for the cameras after you've done a test render. That's something that can only come from using the software and either being pointed there or going "hey, what the hell is that?" Ya know my method, lol -- I play with everything. Too much. I keep starting a tute and then getting sidetracked in playing with stuff. I have no idea how geep stays on target, lol

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)


Nance ( ) posted Fri, 21 January 2005 at 11:41 PM

Not tutes, just communal head-scratching threads, but here's some from long ago on shadow control, and also addressing shadow antialaising and shadows cast by semi-transparent objects, including some sample illustrations.

http://www.renderosity.com/messages.ez?Form.ShowMessage=906924

http://www.renderosity.com/messages.ez?ForumID=12356&Form.ShowMessage=1059682

http://www.renderosity.com/messages.ez?ForumID=12356&Form.ShowMessage=1615561


operaguy ( ) posted Fri, 21 January 2005 at 11:54 PM

Thanks! I love it, I get to throw out everything I've learned, start all over, and pull back all the tossed out stuff afterwards. That's the experience. You guys are great. ::::: Opera ::::: P.S. What's a point light?


ynsaen ( ) posted Sat, 22 January 2005 at 12:03 AM

radial light -- casts light evenly in all directions from a specific point in space. primary use for them is in scene lighting -- lightbulbs, candle, fires. Poser is set up currently for "stage" lighting, more or less.

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)


Nance ( ) posted Sat, 22 January 2005 at 12:19 AM

...and I believe Dr.Geep does also have a tute specifically on ShadowCams.


operaguy ( ) posted Sat, 22 January 2005 at 12:21 AM

Thanks. ::::: Opera :::::


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