I desparately need some clarifications on how certain lights work in P6 and what is good to use and what's not. Basically, I am tearing out what hair I have left trying to create a well lit scene that is as close to realistic as possible. Ok, so what exactly is Ambient Lighting and how do I create it? There are now Ambient Occlusion Lights in P6, so how do they work? What light's work well for realistic renders? is there a way to create a sunlit scene? Ok, probably too many questions, but if any of the experts out there can help me out, I welcome their input. TIA Jim

Objects reflect light on each other. Walls and furniture reflect light from the actual lights in a room and contribute greatly to how other things in the room look. This is collectively known as ambient light and is very important if you are trying to achieve realism for most environments. Unless you are rendering a comedian on a black stage with a single spotlight, you have to do something about ambient light. Before Poser 6, there was no good way to simulate this. People created light sets with upwards of 20 very dark lights, trying to simulate ambience. With Poser 6, we have Image Based Lights, which use a spherically distorted image of an environment (called a light probe) that gives you a cheap and reasonably good (not perfect) way to simulate ambient light. (Really good renderers use a technique called radiosity to actually calculate all the light bouncing around in a room. Very intensive math.)

Thats the up side of IBL. The down side is, it doesn't do specular highlights or shadows. So if you use ONLY an IBL, your figure won't look good. And, because its only an approximation, you still have to tweak things for any given scene. I've never found a perfect-for-all-poses-and-camera-angles light setup.

A couple things to know about IBL - the pose room preview is not going to show you what it looks like. The preview uses a cheap infinite light as a standin for the IBL. IBL doesn't rotate - so if you are trying to spin an IBL around to light a particular area, forget it. Spin the figure instead.

IBL lights need an image (light probe) that describes the environment. There are a few that come with Poser. Look in Runtime/textures/Poser 6 Textures. You can get more from forums and such or make your own.

If you are doing portraits or similar, we can keep things simple. Usually one IBL and one infinite light in front of the figure will give good results. Sometimes I use one more light behind the figure.

The important thing is to manage the overall light balance - if you see washed out yellowy areas on your figure, lower the lights. One more thing - lights alone won't get you realism. You need good textures and some material room tricks to simulate skin properly. Anyways...

Try my simple portrait light setup.

First we'll set up the IBL.

• Delete all your lights.
• Add Light 1
• Set color to White.
• Set intensity to 50%. (You can tweak this later.)
• Go to the Properties tab.
• Click Diffuse IBL
• DO NOT turn on Shadows - IBL shadows creates crap.
• Turn on Ambient Occlusion.
• Click the button "Advanced material properties"
• In the material room, link the Light Color to a new Image_Map node.
• Click the "None" next to the Image_Map Image_Source attribute.
• Click Browse...
• Navigate to the directory mentioned above, and select interiorLightFromSide.jpg
  (You can try others later)
• You should see a silvery ball reflecting a room with a table and a big window to the side.
• Click OK
• Set the IBL Contrast to 0.8. This attribute controls how much the IBL Light Probe is blurred to simulate ambience. The default value is too big - you get little variance.

Your IBL is now ready - go back to Pose room and render. Try moving your camera around and see how your figure looks from all sides.

Your figure should be dark but generally evenly lit, with somewhat more light from the right side.

Now go back to your front view.

Now we'll add the infinite light that will bring out the 3 in 3D.

• Add Light 2
• Set color to White.
• Set intensity to 50%. (You can tweak this later.)
• Go to the properties tab.
• Click Infinite.
• You want Depth map shadows (probably on already).
• Turn on Ambient Occlusion.
• Move the light so its coming from over your left shoulder (if your figure was doing a "Heil Hitler" she whould be pointing at the light.)

Now render.

Hope this helps.

Well I definitely see the improvement from the IBL you put in. See how the shadow is softened in her armpit and other areas where it used to be black?

Where is Light 2 positioned? I don't see highlights anywhere. It's wierd because I see a shadow on her left shoulder. Is that shadow from her head or arm? If so, the light is pointing the wrong way.

The exact position of Light 2 doesn't matter but it has to be pointing at her front. If you zoom out and look down at her, you should see her long shadow behind her on the ground.

Another tip I forgot to mention. It helps to turn off the IBL and do a render with the other light alone. This makes sure you are getting highlights where you want. Whenever you add more lights, it really helps to test render one at a time so you know what affect each is having. Use the properties tab to flip them on/off without changing their intensity. I think you can double click the light dragger widgets or something too.

Message edited on: 09/15/2005 20:55

Light 2 is above her to her right and is pointed at her head. I did a second render with #2's intensity kicked up to 75%, and that helped alot. Sorry, I didn't get back to this last night. Had to put my kids to bed, then Survivor came on. If you check this post again, could you tell me how to change the background colour. Its changed from Poser 5.

Message edited on: 09/16/2005 07:41

Post your latest - I'd like to see how its working for you. Give me full body too.

bagginsbill thanks for these great tips. Question does the position of light 1 make any difference? Do i just accept were poser places it when i create a new light?. could you include the dial settings for these. Also what setting do you use for your render. Thanks again

I don't know why the programmers chose to ignore the possibility of rotating the IBL light probe but they did. Mathematically its a relatively simple operation. However, rotating the light #1 WILL affect your preview - it will light the preview as if it were an infinite light. Because of this, I sometimes move it around a little to help me judge what I'm seeing in the preview and be better able to predict the influence of other lights. Test renders are key here, though. Don't trust the preview for much where lighting is concerned.

Sorry I can't give dial settings for angles - I'm away from my poser machine until Monday.

b.m. thanks! mike