The attached render uses "The Backdrop" commercial product (available at the Rendo marketplace). I am using the one light set that comes with the product, and also the backdrop itself. As you can see, the shadows look pretty hideous.

This is not a question specific to that product, I'm just using that product as an illustration for what I am about to ask.....

... and that is - does anyone know any tips or tricks to get control over shadows that are cast by the main figure on the backdrop. Maybe the use of special cameras, or maybe parenting of camera or lights to the figure or something ??

I'm aiming for more appropriate shadows for good portraits.

Any help appreciated.

Thanks and regards,
Andrew

The main light is shining somewhat up, which not only casts the shadow so it lands above the figure, but also lights the figure in a very unattractive and unusual way. If you're doing a horror flick, use that. Otherwise, tilt the light down.

The shadowcam is your friend. It gives you a preview of where the shadow will hit (directly behind what you see) and you can shape your primary light realtime by clicking on it (lightball on your interface. The one dead center) while looking through the shadowcamera (using mainlight parameter dials).

Those "legs" that do not cast shadows will become apparent why in shadowcam..

Right click workwindow>Camera>Shadowcam

Detail for the newbies here

Thank you richardson, I didn't know that. Never saw it mentioned before!

Attached Link: Shadow Camera Tutorial - compliments of Dr Geep Studios

Here's an oldie but a goodie ... well, da NaySayGuy thought so ... :lol:*

Enjoy.

cheers
dr geep
;=]

For outside views, I use only one infinite light and a modified BB's dome. There is only one sun, (I'v never seen a second one) :-)
Light always comes from above the horizon, and generaly at 30 to 60° above it.

IDL ( remember, light has to touch something to reflect from and create indirect light )

For inside views: The same, main lamps-lights are mostly above our heads.
Some like a candle can be below.

I use one or 2 spotlights, (mostly one for the main light source) and use an ambient on the secondary light sources. Only good if you again use IDL to render.

The relationship between light source and camera position is critical.

"BE" the lightbeam light. Think shadow.

In aviation, we call it "situational awareness". Know what is where, and what will happen in the future.

Poser8 and PoserPro2010 gave us IDL, and forced (in a good and constructive way) us to rethink light in a more realistic way.

Gloss-Blinn-Reflections - coming from secondary objects created more secondary "light" sources, that we did not have before IDL.

Is this not a facinating hobby??

Thanks all. A lot of good stuff to chew on. I did not know about the shadow cam, but I will definitely look into it.

Quote - Thanks all. A lot of good stuff to chew on. I did not know about the shadow cam, but I will definitely look into it.

" ... look into it." ..... :lol:

Let us know what you see.

cheers,
dr geep
;=]

Thanks Dr Geep - I needed that!

Hi Doc,

Thanks for the excellent tutorial :)

I started to get a bit lost from about page 4, onwards. So here are a few questions:

(1) Page 4 - how do you get the main camera directly behind the key light ?
(2) Pages 5,6 - I am not clear why you are urging the viewer to note where the edge of Poser's ground is relative to the figure. What am I meant to be observing here ?
(3) Page 6 - you refer to the "top row" and the "bottom row". What rows ?

Many thanks,
Andrew

You can also go into light properties , find Shadow and set it to between 0.2 and 0.5 (to start). That will give a nicer shadow rather than very dense black. 

Also consider making only one light be a caster of shadows. Turn shadows off on other lights, especially lights meant to 'fill'

I thought the Shadow Cam was only of use for Depth Mapped shadows.  Can anyone confirm or refute this?

4 mathman

1. Make sure you have a "Spotlight"

2. Use the Main Camera parameters to move the camera so it is "looking" through the spotlight.

To be continued ...

Quote - (2) Pages 5,6 - I am not clear why you are urging the viewer to note where the edge of Poser's ground is relative to the figure. What am I meant to be observing here ?

The edge of the GROUND is where the shadow ends.

This is why the shadow may appear to be "cut off" in a different view.

To be continued ...

Quote - (3) Page 6 - you refer to the "top row" and the "bottom row". What rows ?

A picture is worth ............... what you paid for it, no?! ... :lol:

Anywho ...........

The "Top Row" is on the top ... and ... the "Bottom Row" is on the bottom ... ok? ... Ok.

Questions always welcome.

cheers,
dr geep
;=]

Well, Shadow cam... Raytrace... yes or no anyone?

Pretty please?

Quote - (click image to view full size)

4 mathman

1. Make sure you have a "Spotlight"

2. Use the Main Camera parameters to move the camera so it is "looking" through the spotlight.

To be continued ...

Thanks, Doc...

This method seems to me to be problematic. What I mean by that is: you can manually move the Main Camera around using its parameters until you are blue in the face - how do you know when you have positioned it behind the spotlight ? .... furthermore, isn't there a niftier way e.g. by parenting or "point at" or something like that ?

regards,
Andrew

Parenting does not move the item. Point at wont align the light and camera. The spotlight can be visible in preview , as can the camera. Use a different camera to line the two up.  Start by matching the two objects translate and rotate values.

@sam , I dont think raytrace shadows use the shadowcam.  The shadowcam should still give you a good idea of where the light is coming from.

Quote - Thanks, Doc...

This method seems to me to be problematic. What I mean by that is: you can manually move the Main Camera around using its parameters until you are blue in the face - how do you know when you have positioned it behind the spotlight ? .... furthermore, isn't there a niftier way e.g. by parenting or "point at" or something like that ?

regards,
Andrew

re: " ... blue in the face."

Are you trying to move the Spotlight ... or the Camera?

my vote would be to use raytraced shadows.  in the old days they thought ya could only get soft shadow edges with depth-map, but it's no longer true AFAIK.

Quote - re: " ... blue in the face."

Are you trying to move the Spotlight ... or the Camera?

doc, the Camera.

Change DollyX (left/right) and ...

DollyY (up/down) ...

... until the Spotlight's outline is in the center of the screen.

DollyZ will move the camera forward and backward.

Why are you adjusting the main camera trying to line it up with a light? Use the shadow camera. That is always lined up with the light. Yes, it is not used to render a depth-map if you set the light to ray-tracing. But you can still look through it and render with it.

Quote -
Use the Camera's parameters to move the camera behind the Spotlight's outline as shown.

Change DollyX (left/right) and ...

DollyY (up/down) ...

... until the Spotlight's outline is in the center of the screen.

DollyZ will move the camera forward and backward.

Thanks Doc :) ....

@ mathman ........... You're quite welcome.

Hi BB,

re: adjusting the main camera

It is suggested as an exercise - not necessarily a recommendation of the only way to do it.

Having said that ...
You are absolutely correct BB - Using the Shadow Lite Camera (SLC) gives the correct view without the need to adjust anything.  However, using the SLC does not show the Spotlight's outline in the Document window.  My instructions were only intended to educate the viewer and attemp to prompt the viewer to learn some of the nuances of Poser.

cheers,
dr geep
;=]

Quote - My instructions were only intended to educate the viewer and attemp to prompt the viewer to learn some of the nuances of Poser.

cheers,
dr geep
;=]

That's why I love your tutorials, doc. Full of very interesting, little known Poser facts :)

Thank you.

If I wanted to render a portrait (head shot) with a subtle shadow directly behind the head, is there any tricks anyone can suggest to get this effect?

Like this? :blink:

Yes, doc, that is way cool .... :)

Use a Spostlight and "Point At" figure's head.

Adjust Spotlight's position and other parameters to achieve desired results.

Use other "fill" lights (with shadows OFF) as required.

And that's all there is to it.

cheers,
dr geep
;=]

Thanks doc. I'll experiment some more and let you know.

(PS What do you recommend as fill lights ?)

doc, there must be more to it. I have spent ages putzing around with this, but I'm still not achieving what I want. I have a spot with shadows, and a point without shadows. The spot is pointing at the subject's head. I have tried lining up the spotlight using the left and top cameras, as well as going via the shadow cam, to make sure it was looking straight on to the figure's head. Still no shadows.

Try this ...

... and this.

cheers,
dr geep
;]

Here is the latest attempt (clearly still not giving me the result that I want).

... AND ...

If the infinite light is too bright, it will "wash out" the shadow from the spotlight.

Try turning the infinite light off and render it to see what effect you get.

????????????????????????

doc, how can i gauge the distance between the figure and the backdrop wall (bearing in mind that the wall of the backdrop is not at z=0 in the default position) ?

(PS I am using Poser Native Units)

Dr Geep's Scale (DGS) says that ...

1.000 Poser native unit (Pnu)= 100.00 " (DGS inches) or 8' 4"

Therefore,

1" = 0.010 Pnu

10" = 0.100 Pnu

100" = 1.000 Pnu, etc.

1' (12") would be 0.120 Pnu

2' (24") would be 0.240 Pnu

3' (36") would be 0.360 Pnu

etc., etc., etc.

If your figure is in the center of the studio (zTran = 0.000) and you want an object 3' behind the figure, make zTran for the object zTran -0.360 to move it back 3'.

(This assumes that the object is thin ~1-2" otherwise you would add half the thickness of the object (wall) to the distance.

Example:

If the wall object is 1 foot (1' or 12") thick and you want the front face of it 3 feet (36") behind the center of the studio, zTran for the wall would be set to 0.360 (36 DGS inches) + half the thickness of the wall 0.060 (6 DGS inches or zTran for the wall would be 0.420 (42 DGS inches).

Now, the front face of the wall will be exactly 3 feet (3' or 36") behind the center of the studio.

Ok? Ok.

cheers,
dr geep
;=]

Attached Link: http://www.drgeep.com/p4/rws/rws.htm

See Page 6 for using the GROUND Prop Scale for reference.

cheers,
dr geep
;=]

P.S. You can download the FREE Scale prop(s) from my website here
http://www.drgeep.com//FreeProps/FreeProps.htm

I have removed the backdrop prop, and replaced it with a cloth plane. I have set the ztran to -0.24. Unfortunately still no shadow.

Guessing here: If the camera is closer than the light, and they are aligned perfectly, your viewpoint will be such that the head is bigger than the shadow. This is the only explanation of why there is a shadow but you can't see it. This would be confirmed if you moved the camera back and to the side a bit.

Second guess: There is no shadow - you forgot to enable shadows on the light.

Or ........... ?????????????????? :blink:

Or what? Render settings show shadows enabled. He said the "wall" is -.24 (no units specified, so we have to assume he followed instructions and used -.24 PNU, which according to DGS is two feet.) The light is clearly dead center, since the forehead highlight is down a bit, and the chin highlight is up a bit.

All that remains is the shadow is hidden behind the head or there is no shadow.