Building and Using Nebulae: (Layout)

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With the painting of the nebula map done, we can get on with the fun part, and start rendering some nice images of our nebula sitting in a glorious starry sky.

We can also do some tweaking to the nebula in the scene, to make it fit the requirements of our particular scene.


1) Previous Step | Next Step

Open Lightwave Layout and load up the scene we saved at the end of our last Lightwave session: Space_Environment_02.lws.

remember this?

The first thing we will do is replace that nasty temporary image map with our newly painted nebula.

Open the Images editor / panel and select the temporary nebula map.

Click the Replace or Replace Image button (depending on your Lightwave version) and choose to replace the temporary image with the one you just painted.

Lightwave[6] images editor

Once the image has been successfully replaced, save your nebula object so that the change to the texture is retained for later.

2) Previous Step | Next Step

We should now have our new nebula image correctly mapped onto our nebula object.

temporary image replaced with painted nebula

You can try a test render now to see how your nebula looks.

first render

I hope you're pleased with the results you get.

3) Previous Step | Next Step

When we were painting the nebula, remember that I said it was easy to make the nebula less bright if we wanted to?

We can achieve this in any version of Lightwave by altering the Dissolve level for the nebula object. Because the dissolve setting is saved with the scene and not the object, this means that we can easily alter the brightness of our nebula without having to save out separate dark and bright versions of the object.

Open the object properties panel and select the nebula object. Under the Appearence / Rendering tab you will find the dissolve setting. Try setting this to something large like 75% and hit F9 to do a test render. (I have rotated the camera slightly in this image)

nebula object dissolved at 75%

Using this technique, you can quickly set the brightness of your nebula on a scene-by-scene basis so that the background does not overpower the foreground in your renders.

4) Previous Step | Next Step

For those of us who have fully embraced The Joy of [6], there are further tricks we can apply within Lightwave.

Open the Image Editor again and click on the Editing tab, and you will find a whole range of sliders which you can fiddle with to alter your existing nebula image map.

Lightwave[6] image editor

By simply playing with the sliders, you can make drastic changes to the appearance of your nebula.

The only rules you should obey when dealing with nebula maps are these: Do not take the Contrast slider below 0.0, and do not increase the Brightness slider above 0.0, as doing this will compromise the black edges of our image, and produce ugly square edges to our nebula when it is rendered out.

after a few tweaks in the image editor...

Do some playing around and see what looks good and what does not...

5) Previous Step | Next Step

If you want some variation in your nebula renders, you can safely rotate the nebula to and angle that suits you. Try rendering some images with the nebula standing on end, so that you get a vertical stripe of colour in your images.

nebula rotated

You can also stretch the nebula object in the Y axis, to povide a narrower or fatter band of colour than normal.

nebula stretched

One thing to remember is that you should always make your adjustments to the nebula's scale and orientation at frame 0, and make sure that it has no more keyframes (ie. it does not rotate or scale over time) unless you have a particular effect in mind.

When you're finished, save this scene as Space_Environment_03.lws.


© 2000 Kier Darby and Alternate Perspective 3D Ltd.