Lighting has been revolutionized in Poser 6 with many additions. Image Based Lighting with or without Ambient Occlusion has been added. The user can choose from a number of Light Probes. Spot lighting has been improved with a choice of whether the light will rotate around its own axis when moved in the environmental sphere, or revolve around the whole scene.
What is Image Based Lighting? IBL takes a light probe and uses it as a map. A light probe is a 360 degree light distribution contained in a map. Poser comes with a number of light probes and others can be downloaded for free or for a sum from the Internet. The ones in Poser 6 are shown below. Notice they all have different patterns.
In order to get realistic shadows, the Poser 6 manual suggests using Ambient Occlusion. For this effect, Raytracing must be activated in the render setup.
Aiming lights, I believe, is the key to lighting. No matter what light you use, if it is not aimed properly, it will not accomplish its task. I found a few tricks that worked with spotlights and point lights in respect to aligning them to the figure or object. Let's stop here and look at the placement of a figure. The default position of Jessi is the following. Notice the X, Y, and Z axes. They are designated by xTran, yTran, and zTran. Notice everything is at zero.
Now I moved Jessi a plus 1 along each respective axis. I moved the figure +1 unit along the X axis, +1 unit (up) along the Y axis, and + 1 unit (forward) along the Z axis. The position of Jessi is now, 1, 1, 1.
Once you position a figure, look at the X, Y, Z, Tran dials for the Body of the figure and that will tell you what the person's or object's place is in that particular space. Then you can place lights accordingly.
The zTran of the object is especially important. It describes where the image is on the stage in respect to what is in front or in back of the image. If you can line up your lights with the image, then you can also move them to the front or to the back. I will discuss the Point At option (object>point at) later.
An easy way of doing this is to set up lights initially at right angles to Jessi's body.
Once they are placed initially in a square formation, it is much easier to move them.
I have found it easier to use the transform controls to set up my lights. If one has an understanding of how they work in relation to a figure, it is easier to set them up.
The controls above are for the right light while the controls below are for the left light. Notice how the numbers relate to each other. This might seem unimportant if you are going to just move the light anyway. It is understanding the relationship between the position of the lights and the object to be lit that is important.
Let's say I wanted to set up a key light and a fill light in front of Jessi to sort of imitate Studio lighting. The easiest way to do it would be to use the transform and rotate dials. Lets say Jessi is at 0, 0, 0. I need both light to be +Z, +Y, and one each at -X, and +X. The following pictures show how the light started up and how one finished.
Both lights started out at rotations of zero (0) for all angles. For light 2 (see below) the starting positions or coordinates were:
Z=5, Y=5, X=3. The starting coordinates for Light 1 were Z=5, Y=5, X=-3.You can see the final coordinates in the picture above or in the image below. Light 1 was left at its starting position while Light 2 was moved and rotated. (To make Light 1 a fill light it would have had to be repositioned and its intensity light evaluated.)
With everything set at zero to begin with and then moving and rotating the lights in relationship to the figure on axes, it was very easy to position Light #1 and, then, reposition Light 2. A quick change I made was also to change the End Angle to the light so it would shine on a greater surface. The default is an angle of 70 degrees. This setup is not finished at all, but it is a starting place and it is easy to visualize and accomplish.
Even though I first mentioned spot lights and directional lights, Image Based Lighting (IBL) with and without Ambient Occlusion is at the heart of lighting in Poser 6. Before going any further with the tutorial, the reference manual and tutorial manual for Poser 6 are installed automatically. They can be found with the Poser 6 installed files. These topics are discussed in different sections of both the tutorial and the manual. In the two PDFs that are on your system, click on the binoculars and do various word searches.
The best way I found to understand IBL with and without Ambient Occlusion is to look at examples. The first example below shows where the Image Based Light was situated in respect to the image and some of the light settings
When one uses Ambient Occlusion, one does not have to check the shadow box. However, notice the difference when one uses IBL and does not use Ambient Occlusion. The picture was lit only to demonstrate the shadows; it was not lit to demonstrate any other facet of lighting.
Next, I will take the model with the one IBL light and Ambient Occlusion and add two more lights.
I recommend adding 1 light at a time and looking at various combinations. Since I only wanted shadows from one direction, I turned off shadows for the spot light and the infinite light.
Ambient Occlusion has a number of settings. Page 310 in the reference manual describes them. To visually see some of the differences, I changed the settings one at a time, always going back to the default setting.
When I decide to light a figure or a scene, I always ask myself the following questions:
1 - Am I creating an indoor or an outdoor scene?
2 - Am I lighting more than 1 figure?
3 - What mood am I trying to capture?
4 - If applicable, what time of day?
I normally use Poser for creating nude figures to use in other programs. I like to light them in Poser before I bring them into another program to see how they can look or, if I am using them in their rendered state, to bring them into Photoshop, and not have to make too many changes. I either light them evenly, for example, if I plan to light them in a program such as Vue or I light them for mood and, then, bring them into Photoshop where I continue the mood. I have found even lighting is the hardest to accomplish because of the overlap of lights in the center of the figure. However with Image Based Lighting in Poser 6, it is much easier. The key is the light probe that is chosen.
As always, I invite you to visit my web site, Perpetual Visions
- Part II and III of this article will be featured next week, which will include two tutorials using IBL and light probes found in Poser 6.
The Paula Sanders Report is a regular Renderosity Front Page featured column, where Paula investigates and comments on graphic software, techniques, and other relevant material through her reviews, tutorials, and general articles.