Preset Scripts have two big advantages. You non-programmers can snap them into your scenes, modify the script behavior, and connect them to your objects, all without encountering any code. Preset Scripts also offer a standard way for you professional programmers or script-savvy builders to create, modify and distribute Atmosphere JavaScripts.
You have two challenges in using dynamic lighting, besides just building your scene:
Alternately, you can right-click on the "Objects Presets" palette and select "Add Script Presets..." to retrieve the scripts. The "Presets" palettes act as libraries for storing your scene materials. To insert a script into your scene, click on a Preset Script, then on a wireframe view .
You use the "Object Inspector" to set your Preset Script values. Also, the "Script Editor" is available when you double-click a script object. The Script Editor is useful for reviewing any comments about how to use a script that may be included inside the script.
Because my two objects rotate around different centers and have different speeds of rotation, a separate copy of the rotate script is required for each, just as I had to place each rotating object under its own Solid Object. That is, each rotating object is a set of primitives which make up a separate Solid Object, so that each may be animated in different ways.
Multiple copies of scripts might get confusing, so feel free to rename your script objects (but not their file names) to make your scene construction easier to understand.
For example, to install a rotate script, first verify the position of each rotating object in the Object Editor view (access the Object Editor by double-clicking on the Solid Object icon for the rotating object you are working on). Once the proper position is verified, you will probably want to lock your rotating objects so they are not moved accidentally. Then go into Scene Editor view and move your rotate script object to the center of rotation of your rotating Solid Object.
Most scripts require that you set user adjustable values. For instance, to do so for a rotation script, select the script object in your Scene Hierarchy, open the Object Inspector, select the "Target" value and drag the "Whip" tool over the correct Solid Object icon in the Scene Hierarchy. This applies the script to your desired object. Many Preset Scripts use the "Target" value and "Whip" to let you apply them to certain scene objects. Don't be confused by the addition of the "this" keyword to the target object name in the Object Inspector. That's just a standard way of preventing potential problems in your user-modified script.
Finally, set the other values you want. Do not be concerned if changing the values in one script seems to change other scripts at the same time. Only the value in the top "active edit" field will change. Your actual values, down in the values list, will not be affected. If you cannot get a value to "take" in Atmosphere, just use the Enter key to complete your value entry.
Many scripts have useful comments that you should review. Double-click on a script in the Scene Hierarchy list to open it in the built-in Script Editor and read any comments.
- Turn off light rendering calculation for the Sun
- Turn it on for the Background
- Turn it on for Bounce (to help fill in holes and hollows)
- Turn off all the shadow calculations
- For your light source, use a pure white background (sky), that you set to emit light. I use an emit value of about 3 for the white background.
This might also result in a smaller light map file, speeding up your world. One Atmo beta tester even experimented with rendering a large world in pure black. They achieved a very small light map file size. Since the light map makes up a large part of the size of your scene file, careful static lighting and dynamic lighting could yield a significant savings in your scene's download time.
Dynamic light scripts always work in pairs. You must have a "distantLight" or "setDistantLight" script to enable dynamic lighting and control the light "source". You must also install a companion "useDynamicLighting" script to enable dynamic lighting for a particular target Solid Object in your scene - or one for the whole scene. I think of these as "Lights" and "Lit Objects".
Every scene has one built-in distant light by default and you can add more distant lights, using the proper script.
| The 6 Dynamic Light Scripts Script author, Gary Beardsley | ||
| * = the scripts I used in the demo DL = Distant Light | ||
| 1. | distantLight-default.js | Turns on the single default DL built into the scene and sets its qualities. You must also have a "usexxxx.js" script, Like "useDynamicLighting.js" |
| 2. | distantLight-new.js | Adds a new DL to those already in your scene. You must also have a "usexxxx.js" script, like "useDynamicLighting.js" |
| 3. | * setDistantLight-default.js | Sets the qualities of the DL source itself. Seems to be the same as "distantLight-default.js". |
| 4. | useDynamicLighting.js | Enable the use of DL for a Solid Object or Surface Object. |
| 5. | useDynamicLightingForActor.js | Enable the use of DL for an Avatar. |
| 6. | * useDynamicLightingForAll.js | Enable the use of DL for everything in your scene, including all actors. Note: DL currently works with all scene objects! Avatars (Viewpoint of Atmo primitive), Viewpoint objects, Atmo primitives and Surface Objects are all nicely lit by DL. |
| "setDistantLight-default.js" This adjusts the light "source" | ||
| Value | My Setting | Comment |
| Azimuth | 208 degrees | 0 to 360. Position around the horizon. |
| Brightness | 0.8 | 0 to 10. Must be balanced against the brightness you want for your static lighting light maps and against the ambient light value. |
| CastShadows | True | Boolean (True or False) |
| Color | 1, 0.75, 0 | Red, Green, Blue. Mine is yellow-Orange |
| Cone angle | 0.5 | Default. Parallelism of the light rays ("collimation"). How much the light spreads out with distance. Very large values will cause light to spread around the sides of objects. |
| Elevation | 10 degrees | Distance above (+), or below (-) horizon. My demo has low sun. |
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| "useDynamicLightingForAll.js" This adjusts the light's effect on the target(s) | ||
| - The 3 light sources you must balance are shown in red - | ||
| addDynamicHighlights | True | Enable specular hightlights/reflections for Viewpoint objects |
| ambientBrightness | 0.05 | Level of "environment" light (Vs static light Vs dynamic light) |
| anbientColor | 0.25, 0, 1 | Color of "environment" ambient light - I used bluish shadows |
| castShadowsOntoOthers | True | Target objects will make shadows onto other objects? |
| castShadowsOntoSelf | True | Target objects will make shadows onto parts of themselves? |
| diffuseBrightness | 1.5 | Level of dynamic light (Vs static light Vs ambient light) |
| diffuseColor | 1, 0.75, 0 | Color of dynamic light. I used yellow-orange. Notice that this allows you to set a color for each target that differs from the color of the distant light itself. For example, you could have distant light that is white, yet have it be red on one target and green on another. |
| lightMapBrightness | 0.2 | Level of static light (Vs dynamic light Vs ambient light) |
| lightMapColor | 1, 1, 1 | Color of static light. I used white. |
| receiveShadows | True | Receives shadows from DL? Note that objects can be made "transparent" to DL by setting this false, allowing DL to work inside enclosed spaces. |
| useDynamicLighting | True | Does the target object have dynamic lighting enabled? |
If you're not careful, this balancing act can lead to endless tweaking. I recommend that you leave the ambient brightness at zero while adjusting the other two lights. Then add in the ambient, a little at a time, until it just begins to "wash out" the shadows.
I find that if my static light maps are white (as in my demo) that I can use low levels of brightness for the static light maps and high values for the diffuse (dynamic) light.
You can see in the above table that I'm using only 0.2 brightness for static light maps but 1.5 for diffuse. In other words, I want the scene to be mostly lighted by dynamic light, with only enough static light to keep the textures visible and fill the shadows a bit.
The way I arrived at my levels was to adjust the shadows first, so that I could see some detail in the shadowed textures of the wall around the scene. Then I adjusted the diffuse (dynamic) light brightness until I got a bright level on one face of one of the white objects - a face that was reflecting the distant light directly at me. So, I used just enough light to provide good "form" to the large column - from the lightest value of one bright face reflecting the "sun" into my face, down through the darkest values of the shadowed faces.
Never forget that modeling your scene's forms is what lighting is all about. Before the dynamic lighting was applied, I had a pure white scene - a total "whiteout", where form was absent!
In the real world, lights are almost never pure white. In fact, when a scientist, photographer or engineer needs a source of pure white light it is not so easy to obtain! One of the strengths of our human visual system is that it rapidly adjusts to environments lighted by different colors and allows us to perceive a "white". But that does not mean we are not emotionally affected by these subtle color values and our adjustments to them.
Think about it. Even high noon sunlight is somewhat yellow. Sunset light is often orange or pink. Skylight (indirect sunlight provided by the scattered light of the sky) is light blue. Candle light and firelight are quite red. Incandescent lamps are yellow, while some fluorescent lamps are rather blue. Use color in your lighting to emphasize the qualities of your scene and provide clues about your light sources.
You are the Lighting Designer for your stage. If you add dynamic lighting to your Lighting Designer's toolkit, I think you will soon agree that it is a fun, flexible and beautiful creative tool.