Perspector Newsletter, June 2008

Our newsletters often contain useful tips on using Perspector. We have now made all our previous newsletters available online.

Here are some highlights:
Comprehensive coverage of Perspector 4.0.
A fusion of PowerPoint 2007 and Perspector.
Explanation of all of the shape handles.
How to customize the Perspector toolbars.
About shape color.
Alignment and distribution.

Lighting in Perspector

Perspector images can be lit up by up to 5 different lights. Careful attention paid to lighting can make dramatic improvements to images. Lighting can also be used to create interesting effects:

Directional lights vs. ambient lighting

Directional lights shine in a single direction, but do not come from a single point. The light rays are parallel, rather than the light that comes from a bulb or spotlight.

Ambient light is a general level of light that is everywhere in the image. It has no position or direction.

A Perspector image can use up to 4 directional lights, and also has a level of ambient lighting.

Directional lights - stength

In new Perspector images, only light 1 of the 4 directional lights is switched on.

To switch on one of the other 3 lights, choose Image, Lighting, the light you want to turn on, then any of the strengths:

To switch a light off, choose Image, Lighting, the appropriate light, then None (Off).

To make a light dimmer or brighter, repeat the above steps and choose the required strength.

Directional lights - direction

To change the direction of a directional light, choose Image, Lighting, the appropriate light, then choose one of the Position values.

This value indicates where the light source would be if it were an infinite distance away behind the camera. For example, Top-Left indicates that the light source is effectively a long way above your head, behind your left shoulder as you face the image, so the light direction is down-right-and-forward.

If you move the camera in the Professional Edition, the lights move relative to the camera.

Ambient lighting

To change the level of ambient lighting, choose Image, Lighting, Ambient Lighting, and then required level of lighting.

Other lighting issues

Shapes have a shininess property that affect how they respond to lighting. See the March newsletter for a description of shine.

You might have noticed that no shadows are cast by the lights. This is expected as Perspector does not yet render shadows.

Example image

If you're curious to know how the image at the start of this newsletter was created, it consists of a grey sphere with no ambient lighting, and use of all 4 directional lights.

Each light is from a different corner direction, and each is at High strength apart from the Bottom-Right light which is at Medium strength.

The yellow illumination from behind the sphere is actually a PowerPoint oval shape with a "from center" gradient fill.

This image (without the PowerPoint illumination effect) has been added to the Perspector Library. See the Image Watch at the side of this newsletter.