Just wondering what I'm doing wrong.  I was experimenting with lights.  For a plain and simple start, I pointed a spotlight at the camera and rendered it.  I was expecting to see a circle of light.  Instead, I saw nothing.  Does this require volumetric lighting to get a somewhat hazy circle?

  My desire is to do some backlighting of a character to get a shadowy outline, like they do in the opening credits of the Bond films.  Do I do this with spot lighting?  Or do I need to create a "sheet" between the character and the camera and use area lighting?

  Any help would be much appriciated!

Thanks,

Nebula

Volumetric lighting is what you need for that air-haze, smoky/foggy atmosphere look. With volumetrics that will give you those dark shadows in the haze where the figure "cuts" the light.

You do need a background prop behind the lights and figures though for volumetric to work. See my Tickets Please render for an example where I let that background go dark so it did not show.

If you just want a silhouette that's another thing, sorry I don't watch Bond movies so cannot relate to your example! :)

Strum_und_Drang,

  Thanks for the reply.  Actually, a silhouette is probably what I am looking for.  However, your Tickets Please render is wonderful!  Great lighting.  I do understand the volumetric effects tho.  But I guess I was a little suprised when I pointed a spot at the camera and rendered nothing.  I realize the light needs something to illuminate.  But I guess I expected to see a white spot rendered.

  Thanks again!

Nebula

Quote - But I guess I expected to see a white spot rendered.

The reason is that a "light source" in Poser (or any 3D rendering program) isn't an actual object, like a light bulb or the sun. It's more of a reference point for coloring objects that are in the scene.

WARNING: GEEKY, MATH-TYPE STUFF AHEAD.

Everything in 3D rendering is about numbers representing points in space, and colors at those points. I'm going to use ray tracing as an example, but the concept is similar in all kinds of rendering. The important elements of our scene are the Camera, the Render Window, the Object that we're trying to make a picture of, and, finally, the Light Source. Each of these have many different attributes, but for this example, we'll concern ourselves with just a few.

The Camera is a fixed point in space (X, Y, & Z coordinates), and points in some direction. In this example, it's pointing in the general direction of the Object. The Render Window is an imaginary rectangle between the Camera and the Object. It represents the actual image that we're going to end up with. The Object itself consists of many connected polygons (usually triangles and squares), each of which is represented as an X, Y, Z point in space (called a Vertex). Each polygon in the object has a color value, four numbers representing it's red value, green value, blue value, and transparency, respectively. Commonly, this color comes from a texture map that has been applied to the object, but may come from a procedural shader, too. Finally, there is the Light Source, which is also a fixed point in space. It, too, has a color value.

For each pixel in the final image, the rendering engine (for example, FireFly in Poser) is going to "shoot a ray" at it. The word ray, in this case, is used in the mathematical sense of "half a line". What this means is, the program is going to mathematically calculate a ray beginning at the Camera (A), and intersecting a point in space that represents the pixel being calculated in the Render Window (at the X). The program will continue drawing the ray to see if it intersects any of the the 3D objects in the scene. When it does (at B, in this case), the program draws a second ray from that contact point (B) to the Light Source (C). If the second ray intersects a light source, the program uses the light's color to mix with the color of the Object at the intersection point, modified by the angle that the second ray makes with the object's polygon, to determine what actual color appears at that point. That color is then written out for the pixel, and the engine goes to the next pixel and starts again, until the image is finished.

If the first ray never hits an object, light sources never come into play. Instead, the program draws a background color in the pixel. If the second ray hits another object instead of a light source, the pixel shows a dark color, since it's in shadow. So, pointing a light source at the camera doesn't do anything; since the camera never sees an object, it never looks at the light source.

In an actual scene, many, many factors modify this process. These factos can include transparency (which will cause yet another ray to be drawn, reflection (which will also cause more rays to be drawn), fog, light intensity & spread, ambient color, and on and on. But that's the basics.

=== END OF GEEKY STUFF ===

Don't know if that's of interest, but maybe it helps.

CaptainJack1,

  Thanks for your explanation.  I knew some of this but your description helped to fill in the gaps.  Very well done!

   So, to do a silhouette, do I need to do it the "real world" way?   By adding a transparent plane between the object and the camera?  Will that work?  Is there a better way?  I was hoping to be able to do some animation with the shadowed character.

  Thanks again for everyones input!

Nebula

before doing something complex, try simply backlighting a figure.  no ambient or front lights.  i'm pretty sure you'll get your silhouette.

Quote - CaptainJack1,

  Thanks for your explanation.  I knew some of this but your description helped to fill in the gaps.  Very well done!

Thank you, I'm glad it was useful. I never can tell when it's safe to go off on a geeky, technical jag... at parties and such, my wife usually puts a clamp on me before I make everyone's eyes bug out. :lol:

I've never done a silhouette render inside Poser before, but I'm sure that some strong back lighting behind the characters would do the trick. You may need to experiment with the way you line up the lights, and the lights may have to be very close to the back of the figure so as not to light up any props between the figure and the camera. I'd recommend using the Top Camera view to line up the lights, figure and main camera; it may help to put a small prop behind the main camera for alignment purposes.

I recently made an animation in silhouette for someone, but I did some of the work outside of Poser. I set up the animation inPoser the way I wanted, and rendered at a very low quality setting (since the lights and textures weren't going to show up anyway). I exported the animation as a series of PNG files. Then, I made a script in Paint Shop Pro that would reduce the luminance of the image so that it became all black on a transparent background, then made a background layer of all white. I ran the script in batch mode on all of the PNG images. Finally, I combined the images into a single animation, using VideoMach, which is a pretty handy and inexpensive tool, if you do a lot of animations.

Providing backlighting only to a figure can indeed make a silhouette, but you will get some highlights on the curves of the body etc, and of course any hair or clothes. You might want that, for the moulding and shaping it performs.

However, if you want the hard almost 2D effect, then you will have to provide a background, strongly light that, and leave the figure dark.

Experiment with relative distance of the background to the figure, and where you place the lights. Spolights will be best as they throw the light only one way.

So, from back to front:

A background, some lights for the background only, the figure, and then the camera.

As for the "real world way" to do a silhouette, well the above is it. The idea of having a sheet between the camera and the figure is not silhouette, it is shadow.

Trust me, in the "real world" I am a lighting designer... ;)

I just now tried something in Poser that had a useful silhouette effect... I put a light directly in front of the character, pointing at the character, set it to all white (value of 1.000 in each of red, green, and blue) and set the energy to -100%. The negative energy appears to have removed all of the light from in front of the character. I put another light behind the character, and the front is still black.

oh, and of course if you're using poser, you can render a plain silhouette.  i believe it's one of the styles you can choose.  i'd have to go home and check, but it i believe it's a preview option you can use as an option to make movies with.  for a while, there were lots of running dork silhouette flash animations out there.

CaptainJack

Your experiment brough back memories of the Dark Sucker Theory.

http://paul.merton.ox.ac.uk/science/darksucker.html

:)

Quote - Your experiment brough back memories of the Dark Sucker Theory.

Ah yes... I love that. I haven't heard about the Dark Sucker for many years, thank you for jogging the ol' memory cells. That's a good one. :biggrin:

display > document style  (or figure or element) > silhouette.  the silhouette will be the color of your foreground color.  in render settings, choose the preview tab, and turn on antialiasing (unless you want jagged edges).

Excellent!  I will give it a try.  Thanks to everyone!

Also, what a theory!  The Dark Sucker...... 

Quote -

WARNING: GEEKY, MATH-TYPE STUFF AHEAD.

Don't know if that's of interest, but maybe it helps.

I added that to the lighting tutorials thread that I have going.  It might be "geeky", but it explains it clearly. I even understood it!!!!!!!!  LOL

Quote - I added that to the lighting tutorials thread that I have going.  It might be "geeky", but it explains it clearly. I even understood it!!!!!!!!  LOL

Why, thank you very much, Acadia. I must say, I'm honestly quite honored to be a part of your collection.

Put a back light behind the figure, shining straight at the square. This light must use depth-mapped shadows, otherwise this won't work. The Fastscatter node will translucently light the square with light from the backlight, except where her shadow falls on the square.

You can light the front side as well, or not. Here I placed a table in front of the square and used a dim spotlight to light the front side. You can see both the figure shadow from the backlight and the table shadow from the frontlight.

sort of a window shade effect.  interesting. 

bagginsbill,

  This is awesome!  Just what I was looking for!  I have been working with it and so far it's doing great!  Once question, is there a way to get rid of the aliasing?  I was using Firefiy but tend to get some heavy aliasing.

  Otherwise, this is fantastic!!  Thanks so much!!

Nebula

Neb,

I assume by "aliasing" you are refererring to some pixellation somewhere in your scene, otherwise known as "jaggies"? So you want anti-aliasing?

If you're getting jaggies in the shadow, try setting the light's Shadow Blur Radius (in Properties) - this softens the edge of the shadow.

If it isn't micro-pixellated, but rather the edges seem to be squaring off (bigger squares than a pixel) then it's because your shadow map size is too small. Go to the light's "Map Size" (in Parameters). The default map size is way too small. Go for at least 800, maybe 1200 or 1600. Shadow  maps are actually images that get automatically generated and then used as a mask on the light. When this image is too low resolution, you can see it's pixels. Raising the shadow map size makes the shadow image pixels smaller and therefore more accurate shadows result. Be prepared to wait a lot longer for the shadow map calculation. I suggest you enable the menu item "Render/Reuse Shadow Maps". This will only calculate the shadows once. If you move things, click "Render/Clear Shadow Maps" to get it to recalculate.

If you're talking about general jaggies everywhere, go to Render Settings (I always use manual) and make sure the "Pixel samples" is bigger than 1. I usually use 3, but sometimes 5. If things are blurry as a result, lower the "Min shading rate" - I usually use .5, but in extreme cases I use .2. If you ever render a textured object and the texture looks blurry and you've loaded it at full size (Max texture size is at least as large) then the "Min shading rate" reduction will bring out the details.

bagginsbill,

    This is fantasic stuff!  It's working great!.  Thank you again.  I would like to ask, I am limited to 1024 for the lights Map Size.  Can't go any higher.    I hope to post something next time I write.

  Thanks again!!!!

Nebula

Also, what do I need to do to open the lights Map Size to something larger than 1024.  It's currently limited to 1024.

Thanks again!!

Nebula

That looks fantastic.

Screenshot above - this is the parameter you're trying to set, right? It doesn't have a limit at 1024, unless you have a wonky parameter setting. 

If this is the paremeter you're talking about (it's the one I'm talking about) and you can't set it higher, click the black triangle to the right and select "Settings ...". My settings are shown. If your max limit is too low, raise it.

bagginsbill,

  Duh, I should have thought of that one myself.  I will have a look.  Yes, that is the parameter I was talking about.  And thank you for the compliment.  I don't usually upload very much, always wanting the "perfect" render.  I need to get over that.

  Again, thank you for all your help!!

Nebula

Attached Link: silhouettes in P5 thread.

Raven,

I certainly expected the answer to be yes. But I tested it before I posted. The base shader node has Translucent controls, and this was what I understood them to be for. However, at least in P6, it doesn't work. Face_off found this as well. The translucent color input behaves just like the ambient color input or the alternate diffuse color input or the refraction color input. In other words, whatever you plug in or set, it gets added to the render unmodified by light or shadows.

Raven,

I'm curious - could you try it? I have Poser 6 SR3 at the office, and it didn't operate correctly. I have SR2 at home, just for this reason, I'll try it there and report.

You try too, just in case I'm doing something wrong. Because I really was going to explain that the translucent color and value should be used, but it didn't give the shadow for me.

The picture show the normal square prop with translucency. I am using a single spotlight, set behind Woody the Mannequin, pointed at the camera. Ray-traced and shadow-mapped shadows give the same effect. 

Hmm, this is a rather annoying facet of SR3. I wonder if the translucency node works correctly in P7?

Ah thanks so much Raven. Now I know more and less.

I always avoid the double-sided square cause it never works right ever ever. So I didn't even think to try that one.

Hmmm. But the clue is that for a realistic solid object with a separate front and back side, perhaps translucency works right?

Oh also try this: put a one-sided square in. Turn it around 180 degrees (Y rotate). Now render. The translucent shadow shows up on this, without translucent color/value and without a fastscatter. It just shows up.

Looks like Neb is on the way to getting want he is after.

I still maintain that this is strictly a shadow, and not a silhouette, but its all good.

As for the Poser square, it drives me nuts with that striping effect, and more recently I found the cube did something similar as well in one project I was doing.

Strum,

  I guess I would have to agree that it is a shadow.  Most;ly because it is a 2D image.  What do you consider a silhouette to be exactly.

  As for the striping effect, I've had no problems there.  I did exactly as bagginsbill suggested and it's worked out great.  Now I just need some gymnastics motions to work with.

  Thanks again to everyone!!

Nebula

sil·hou·ette     /ˌsɪluˈɛt/ Pronunciation Key - Show Spelled Pronunciation[sil-oo-et] Pronunciation Key - Show IPA Pronunciation noun, verb, -et·ted, -et·ting.–noun 1. a two-dimensional representation of the outline of an object, as a cutout or configurational drawing, uniformly filled in with black, esp. a black-paper, miniature cutout of the outlines of a famous person's face. 2. the outline or general shape of something: the slim silhouette of a skyscraper. 3. a dark image outlined against a lighter background. –verb (used with object) 4. to show in or as if in a silhouette. 5. Printing. to remove the background details from (a halftone cut) so as to produce an outline effect.

Having pasted the definition, I'd argue that nowhere in the definition is there a qualification of how the effect is produced. It simply characterizes and effect, i.e a dark monotone outline against a light background. A silhouette is sometimes a shadow but not always, and a shadow is sometimes a silhouette but now always. But when it is both, then arguing that it is a shadow and not a silhouette is just silly.

That's like looking at a picture of Emiril and arguing "that's not a chef, that's a man".

I can achieve "silhouette" by drawing one, masking a photo, casting a shadow on a translucent screen, etc. Quibbling about the mechanism is silly.

Defininition 3) above is closest to what I would call a real world silhouette, as in made in real life with real 3d objects.

So, it could be the outline of a ship at sea against the brightness of the sky behind it, or really any other situation whereby a figure or object is placed in front of a backround that is substantially brighter than itself.

I would knock out a quick render to illustrate, but I am about to jump on a plane and head off to do a gig and will be away from Poser for three weeks.

Ditto in reference to the striping on the poser square, but you try lighting it directly and rendering it and you'll soon a situation where it'll look ghastly! :)

I was typing my post at the same time as you were typing your second one there!

I am happy enough to accept your point of view, but I was/am speaking as a lighting designer, and this whole thread started as a lighting question. Under those parameters, the difference between silhouette and shadow are easily defined.

Ah, but Sturm I'm picking nits here and you can't just wave your hands like that :)

"this whole thread started as a lighting question"

No, it started as a shadowing question.

Nebula's original posting said:

"My desire is to do some backlighting of a character to get a shadowy outline"

It was you, Sturm, who first talked about silhouette:

"If you just want a silhouette that's another thing sorry I don't watch Bond movies so cannot relate to your example! :)"

But as I said sometimes a shadow is a silhouette, and sometimes it's not. But when the shadow is a silhouette, then by definition the silhouette is the shadow. In this case the shadowy outline was indeed a silhouette, and it is what was asked for.

I understand that you can set up a situation where the background scene behind some characters is so much brighter than the characters themselves, that they end up forming silhouettes on the film if you set your shutter speed up high, and that these silhouettes are not shadows. Yes there are other kinds of silhouette. What exactly is your point? My point is that when a shadow forms a sillhouette, then that shadow is called a sillhouette.

I'm objecting in particular to your obfuscating phrase "strictly a shadow, and not a silhouette". The set of all possible shadows and the set of all possible silhouettes have a non-empty intersection. The scenario we've created here is one where the resulting image is both a shadow and a silhouette at the same time. It is not meaningful to make the statement you made.

Are you just trying to confuse people? This issue is important to me because I constantly run into people on Rendo who use words they don't mean, and the conversations get very confused. People talk about, for example, the surface facing away from a light source as being "in shadow" but it's not in shadow. Being in shadow means that the surface would be receiving and reflecting light from a light source, but that some other object in between is blocking the light. See what I mean? And yet these people think the unlit side is a shadow and are trying to adjust the brightness of this surface by manipulating shadow parameters.

This is why I care - because being imprecise about the words results in imprecise thinking. I am trying to correct the precision by which we use the term "sillhouette" - it is an effect resulting in a solid (no interior detail) shape against a light background, said shape being clearly the depiction of the outline or cross section of some real object. The term in itself has nothing to do with light, despite what you may think. However, light and shadow are capable of creating sillhouettes. 

Am I clear now?

Attached Link: my bond type anim :)

Raven,

  Wow, that was really cool!  Espically the volumetric effects.  12 hours is like forever.  I so wish rendering speed could be improved.

  I would also like to ask, where did you get the animation motions for her??  Was that V3 or some other character?  Her movements looked really smooth.  Where did you get them??

  Thanks again and great animation!!

Nebula

Attached Link: audiomotion bvh fles

I forgot to say, that was using the new Victoria 4 from DAZ.

Great!  Thanks!  Which character did you use?  V2, V3, what?  Did you have to tweak it to get it to work smoothlty or did it just work?

Thanks again!

Nebula

That was very cool Raven. In the right hands (like yours) Poser does some very impressive stuff.

Nebula, it was the new Victoria 4 I used. I didn't have to tweak the bvh. It did come up with an error message about a bodypart but I ignored it, and it worked fine.

bb, thanks, coming from you, as someone who can make Poser do some darned impressive things himself, that means a lot! :)

Raven,

  Yes, I went to the website you listed and downloaded there Female_Walk.bvh.  I imported it in on V3 and it gave the same error yours did, (no Chest reference).  But V3 seemed to walk just fine as well.  Would your Stances file be something you could legally send me?  I'd like to mess around with that one if it's possible.  I purchased V4 on Sunday and have worked with her a little bit.  So far she's been great.

  What kind of site is audiomotion?  They had a few bvh files available to download, mostly male motions.  But I didn't see any kind of packages you could purchase or anything.  Do you or anyone know where some good motion files can be had..... economically of course.  The walk cycle I downloaded was very smooth but a bit over the top.... kind of like a street walker or something, if you know what I mean.

  As always, thanks for the responses!!  GREAT STUFF!!!!

Nebula

There are quite a few BVH files at Michael's Blender Site, free for personal use. I've never tried any of them with Poser, but you may want to give 'em a shot.

FYI, there's a new tutorial up at DAZ on making silhouettes on a dark background that might be of interest.

BagginsBill, Raven,

  Hello again.  I have another lighting question if you might have a minute to take a look?  You can find it here:

www.renderosity.com/mod/forumpro/showthread.php

Thanks!

Nebula