Build a Better Starfield (Layout)
Now that we have built the geometry for our starfield, we can start to add more realistic surfaces and set rendering options so that we can finally render our new starfield scene.
A lot of the techniques described here were initially suggested by Mojo of Foundation Imaging, so if you recognise some settings, that's where they're from.
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Begin by opening Layout... (duh!)
Before we load our starfield object, we will add a Null Object to act as an overall parent for all the scenery in our project. This will facilitate any tweaking of the rotations of the starfield(s) later on.
Add a Null Object now, and call it Space Scenery Parent.
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Now load up your starfield object and parent it to the Space Scenery Null.
If you look through the camera at this point (press 6 on your numeric keypad), you will see that Lightwave has automatically positioned the camera outside the starfield globe so that the camera can see the whole object. This is not what we want, so reset the position of the camera to somewhere in the middle of the starfield globe and rotate it to your own taste.
|Camera positioned in the center of the starfield globe|
You may also want to decrease the Grid Size slightly so that the grid squares are visible. Do this using the square brackets (' [' and ']' ). The image above has the grid size set to 50km.
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Before we go any further, open the properties for the starfield object (select the object and press p).
In the Object Properties window, click the 'Rendering' tab.
|LW object properties|
Set the Object Dissolve to 15%.
Set the Particle/Line Thickness to 3.0 (do not use 'medium' because Lightwave  renders single point polygons in a different way from Lightwave 5.6)
Turn off ALL shadowing options for the starfield object (Self Shadow, Cast Shadow, Receive Shadow).
These steps ensure that the starfield will render correctly, without accepting shadows from other objects, and at the correct size.
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Close the Object Properties / Objects Panel and open the Surface Editor / Surfaces Panel. (Although Lightwaves  and 5.6 call this window different names, I will refer to it as the Surface Editor from now on... don't get confused.)
In the Surface Editor you will see a whole bunch of surfaces defined, including Stars 01 to Stars xx and Magnitude 0 to Magnitude 5.
We know all about the surfaces called Stars xx, because we created them ourselves, so what are these 'Magnitude x' surfaces all about? These are the surfaces that were applied to the ACTUALSTARS.LWO object that we incorporated into our starfield, and luckily, the surface settings are pretty good, so we won't need to alter them.
What we do need to alter is the surface settings for our own star surfaces.
Begin by selecting the surface called 'Stars 01' and setting its surface attributes as follows:
|Translucency (LW only)||0%|
|Bump (LW only)||100%|
If you are using Lightwave , click the Advanced tab and set Additive Transparencyto 100%.
The Additive option will quickly become your friend when doing space scenes. What it does is it tells the renderer to ADD the colour of the surface with Additive applied to whatever is behind it in the rendered image. In plain English, this means that a surface with Additive applied will never make an area darker by its presence.
An example: You have a bright blue nebula with a bunch of dim stars in front of it. If these dim stars do not have Additive specified in their surface settings, they could potentially render as dark patches on top of a brighter background. This would be bad. However, if they had Additive applied, they would be incapable of making the area they occupy darker, so they would render brighter than the nebula.
|the effect of 'Additive' left: off, right: on|
The above pair of images are a very extreme example and are fairly ugly, but they demonstrates the principles.
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You may have noticed that the surfaces brought in from the ActualStars object have a texture applied to them. They use a simple fractal texture that moves across the stars in order to create a certain amount of glimmer and twinkle to the stars.
We will add our own version of this texture to our own surfaces, just to add a little more variety to our stars.
Making sure that you have Stars 01 set as your current surface, click on the or (depending on your version of Lightwave) next to the colour setting in the surface editor to add a texture to the colour channel.
|adding the fractal texture|
In Lightwave , use the settings shown above.
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Now that you have set up 'Stars 01', copy the surface settings from this surface and paste the settings back to all of the other 'Stars xx' surfaces.
To do this in Lightwave , right-click on the name of Stars 01 in the surfaces list and select Copy from the pop-up menu that appears.
Now right-click on the name of Stars 02 and select Paste from the pop-up menu.
Continue doing this until you have pasted the settings into all of your Stars xx surfaces.
Hopefully, all your Stars xx surfaces will now have the same settings as Stars 01.
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It is now time to set the correct colours for your stars. We will be using the stars' colour to define how bright the stars will be in space, rather than using the luminosity setting, which is set to 100% for all of the Stars xx surfaces.
Therefore, for stars that you want to be very bright, use a very bright colour, such as 255,252,232 and for stars that are more dim, use a darker colour such as 45,2,70.
The colours you choose are entirely up to you, but as a guide, these are some of the colours I use in my starfield object:
|Stars 01: 227,232,253||Stars 06: 056,061,029|
|Stars 02: 006,006,172||Stars 07: 137,138,113|
|Stars 03: 252,220,218||Stars 08: 106,105,079|
|Stars 04: 075,073,107||Stars 09: 234,235,194|
|Stars 05: 205,153,154||Stars 10: 108,139,142|
Try to get a good range of colours for an authentic-looking starfield.
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That would appear to be everything! Save your object now.
Let's test how this thing renders.
Go to the Camera panel (select the camera and press p) and set the following options:
Pixel Aspect: 1.0 (Square Pixels)
Antialiasing: Enhanced Low
In the Render Options panel, set the Render Display to QV so that we will get a real-size display of our image.
Now hit F9 and let's see what happens.
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What did you think of that? I know what you're thinking: "It could use more stars".
That's easy to fix. Open the objects panel and make two clones of the starfield object. (In Lightwave , the cloner is accessed through Actions \ Add \ Clone current item ).
Select the first clone object and set it's rotation at H=120, P=0, B=0. Now select the second clone starfield and set its rotation to be H=240, P=0, B=0. This will prevent any obvious repetition of star patterns in your renders.
Hit F9 again and how does it look? Muuuuuch better! We could do with a little more variation in the stars' brightness and size though.
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Let's add a bit of variation to our two clone starfields.
Select the first clone starfield and change its Object Dissolve level to 55%.
Change the Particle/Line Thickness for this object to 2.5 pixels.
Select the second clone starfield and set its Object Dissolve level to 65%. Also, set the Particle/Line Thickness for this object 1.5 pixels.
Render again and you've got a pretty darned good starfield.
|finished starfield scene|
A rendering of the camera tumbling in the starfield
Save your objects and save your scene as 'Space_Environment_01.lws'. We will return to this scene at a later date.
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A few other important things to note for scenes including a starfield:
- If you are rendering an animation and your camera is going to move or rotate in a scene with a starfield (or any kind of Single Point Polygons) you MUST turn on Particle Blur in the Camera Settings panel. Without this effect turned on, any animation showing particles will have very nasty, flickery stars. If the camera makes any very quick rotations, the resulting rendered frames may look a little odd when you view them as stills, but trust me, it all works out when you put the frames together and playback the animation.
- When you are animating your spaceships or whatever else you have in your space scenes in OpenGL mode, you may find that you are unable to see the stars in the background of the OpenGL view. This simply because of the way Lightwave treats OpenGL. If you increase the grid size significantly using the square bracket keys, the stars will magically appear. They will always render when you press F9 or F10, regardless of whether they are visible in OpenGL mode or not. Likewise, you may find that you can only see the stars in OpenGL and your ships are missing. Again, fix this by altering the grid size with the square bracket keys.
- Single point polygons in Lightwave  are rendered in a different way from Lightwave 5.6. As a result of the new rendering process, you should always render your Lightwave  starfields with Enhanced Antialiasing (camera panel) turned on to avoid flicker and harsh edges
|© 2000 Kier Darby and Alternate Perspective 3D Ltd.|