Matching Bryce Backgrounds in LightWave Scenes

I've been getting letters lately from people who are familiar with Bryce, but are interested in moving to LightWave.

Many of them point out that LightWave is much "harder" than Bryce, and this is undoubtedly true. The learning curve is part of the price that we pay for such a powerful and flexible program.

However, when deadlines loom, it's often easier to go ahead and use the background scenery that's already been set up in Bryce, instead of trying to re-create it in an unfamiliar program, no matter how powerful that program is.

But how?

The easiest way is to use the LightWave Composite capabilities, and just import an image of the Bryce scene to use as a Background. However, you'll still want to match the sun and atmosphere settings, so that the LightWave objects in the Foreground will blend seamlessly into the scene.

Scene in Bryce. Click for larger view.

In Bryce, set up the background exactly the way that you want it. This should include the Atmosphere (Sky & Clouds) and all the terrain that's in the background. Don't include anything that will move during the animation, or anything that any animated character will step behind. It's easier just add those things in LightWave.

While doing this, make sure that Link Sun to View is disabled.

Copy down settings for Color, Azimuth and Altitude

When you've got it just the way you want it, open the Sky Lab, and note the Sun settings from the right side. You'll need the color, the Azimuth, and the Altitude.

The Bryce RGB Color Picker

You can find out the RGB settings for the color by holding down the Option/Alt key while clicking on the color swatch. Those are the ones you'll want to copy down.

Note Shadow Intensity and Ambient Color.

Note the Shadow Intensity from the bottom right of the Sun & Moon tab. Write down the RGB values for the Ambient color, too, while you're here.

Copy down all Fog and Haze settings.

You'll also want the settings for the Fog and Haze, from the Atmosphere tab. (I keep a whiteboard next to the computer for all of these notes, by the way. It makes it easier, and saves trees. <g>)

Choosing Export format (Mac panel shown.)

When you've got all of that, render the image the size that you want for the finished animation (or still picture,) and export it in .psd or .tiff format. We're ready to move to LightWave. If you want to follow along, you can grab the .jpg file to use as the Background here. You can see a list with the values you "copied down" here.

Choose Compositing Options from the Window menu.

Open Layout, and go to Window > Compositing Options (or tap control+F7) to open the Compositing tab of the Effects panel.

Choose (load image) and browse to the BryceMistyMountains.jpg image.

Click on the drop down menu in the Background Image section, and load the prepared image. This will be the background, and will be used to replace any "blank" pixels in the finished LightWave render.

Choose "Background Image" from the Camera View Background in the Display Options.

Tap d on the keyboard to open the Preferences Pane to the Display Options tab. At the very bottom, on the Camera View tab, click the Camera View Background drop-down menu, and choose Background Image from the list. That will allow you to see the Bryce image in any viewport set to Camera View while you work.

With the Camera selected, drag in the Camera View viewport to change the Pitch. Click for a larger view.

Now we need to change the Position and Rotation of the camera so that the horizon in Layout matches the horizon that was used in Bryce. Camera position doesn't work exactly the same way, so you'll have to eyeball this one.

Select the camera, and tap the y key on the keyboard to get the Rotate tool. Drag in the Camera View viewport to change the Pitch of the camera, until the line that shows the horizon matches the horizon line in the image. Be sure that you keep the Heading at 0° while you do this. (Or just fix it by using the HPB buttons at the left of the window when you're done. Remember to tap the Return key to leave the text fields.)

With the Camera still selected, switch to the Move tool, and drag to show more Ground. Click for a larger view.

Tap the t key to get the Move tool. Using the RMB (Right Mouse Button) drag up in the Camera View viewport, to change the cameras position on the Y axis, until the grid matches the ground plane in the image. (Assuming that you have one there, of course.)

Type in the equation; LightWave does the math!

We're going to use the default Distant Light to reproduce the Sun in Bryce. So select it, and tap the y key so we can change the Rotation.

The Rotation text fields, at the far left of the window, are labeled H, P, and B for Heading, Pitch and Bank. The Heading is equivalent to the Azimuth setting in Bryce; but it's offset by 180°. In other words, an Azimuth of 0° will put the sun directly in front of you in Bryce. In LightWave, a Heading of 0° will make point the light right up the +Z axis, which would put the sun directly behind you. To compensate, we'll add 180° to the Azimuth setting from Bryce.

In addition, the Bryce camera is at a 45° angle by default. The LightWave camera has a default rotation of 0°. So we'll add an extra 45° for that.

Since LightWave can do arithmetical calculations in the dialog boxes, all you need to do is type the Azimuth, the + sign, 180, + and 45 into the H text field. So, in this example, we'd just type in 228.3+180+45. Tap the Enter key, and the correct value of 453.3 will appear. (If you want to subtract 360, so it's not hyper-rotated, you can. But it really doesn't make any difference as far as I know.)

Enter the Bryce Altitude in the Pitch field.

The Pitch is equivalent to the Bryce Altitude, so just enter the number. In this case, it's 56.4.

Drag the RGB numbers to adjust the light color.

Tap the p key, to open the Object Properties panel for the Light. We need to set the color so it matches the Bryce Sun. (Unless the Bryce sun was white. Since that also the LightWave default, you can skip this step if that's the case.)

All you need to do here is drag on the RGB color numbers in the Light Color field. Drag right to increase the number, and left to decrease it. Set them to match the RGB colors in Bryce; in this case, 255, 198, and 151. (Or, if you find the numbers too hard to read, tap the color swatch to open your Color Picker, and type them in.)

Click with the RMB to toggle to HSV, and drag Value.

There isn't a Shadow Intensity setting in LightWave; but there is a Shadow Color setting. To access it, click on the Shadows tab at the bottom of the Light Properties panel.

To get the Shadow Color to match the Shadow Intensity in Bryce, we need to change the Value. Click on the RGB colors with the RMB (Right Mouse Button) to toggle to Hue, Saturation, and Value.

We need to convert the Bryce percentage of shadow into a number that shows the amount of white from 0 to 255. (100% Bryce shadow equals 0 Value.) The formula is ((100 - Shadow Intensity) / 100) * 255.

So, first, subtract the Shadow Intensity percentage from 100, so that you're working in the correct direction. Then divide by 100 to change the percent into a decimal value. Multiply that by 255 to get the correct number.

In the example scene the Bryce shadow value is 71. Subtract that from 100 to get 29. Divide by 100 for .29, and multiply by 255 to get 73.95. Slide the last number (the Value) in the HSV field to 74, and you'll have (roughly) 71% shadow intensity. (These numbers seem similar; but that's just coincidence. If the Bryce shadows were 25%, you'd have a shadow Value of 191.)

You don't have to move the light, since the physical position of Distant Lights is disregarded. So the Sun is now set. Anything you put in the scene and render will appear to be lit by the same sun that's lighting the sky and terrain.

Click the Global Illumination button to open that panel.

While the Light Properties panel is open, let's go ahead and match the Ambient Light. Click on the Global Illumination button, at the top of the panel, to open the Global Illumination panel.

Set the Ambient color by dragging the RGB values, as before.

In the second section, you'll see the Ambient Color settings. Change the RGB values, just like you did for the Light, to match the Ambient Color from Bryce.

In Bryce, the Ambient Intensity is set on a per material basis. In LightWave, the Ambient Intensity is applied to everything in the scene equally. For that reason, it's pretty much considered "evil" here. However, if you are using an Ambient setting on your Bryce terrain, you might want to give it an Intensity that will match that setting, or be slightly below it, just to help the objects blend in a bit better. Don't go over 15% or so, though. It'll just look bad.

When you've finished changing the settings, close both panels. (The Light Properties panel will appear when the Global Illumination panel is closed.)

If you want your foreground objects affected by Fog or Haze, you'll need to set those up, too.

Set up the Linear Fog to match the Bryce Haze.

To match the Haze setting in Bryce, we're going to use LightWave Normal Linear Fog. So tap control+F6 (or go to Window > Volumetrics and Fog Options... ) to open the Volumetrics tab of the Effects panel.

Change the Fog Type to Linear, and set the Max Distance to something fairly large, like 500 m or more. (This will depend on the distance from your camera to the farthest object.)

Leave the Min Amount at 0%, but change the Max Amount to the greater of the Density or Thickness value of the Bryce Haze; in this case, 44%.

You may need to tweak these settings, but this will give you a good "jumping off" point.

Finally, and most importantly, match the Fog Color settings to the Haze color from Bryce. (That part won't need tweaking!)

Add Ground Fog, and Double Click to edit it.

For Bryce Fog, we're going to use the LightWave Ground Fog, so choose it from the Add Volumetric drop-down menu at the bottom of this panel.

Double click the Ground Fog line to open the Ground Fog Options panel.

Use Fast Fog, and set all options, including Color.

Choose FastFog from the Render Type drop down. (This one matches Bryce Fog better, and is also faster to render.)

For Top, put in the Base Height value from Bryce, in cm. (Bryce uses its own unit, but I've found that converting it to cm usually gets me into the correct ballpark.) For Bottom, type 0 m. (This matches the Bryce fog, which tends to start at ground level. In LightWave, the fog can start anywhere, but it will also start to thin from that starting point.)

For Falloff use 100 minus the Bryce Density value. (This determines the rate at which the fog thins, from bottom to top, just like Bryce Density; but the values are reversed from Bryce settings. In other words, 10% Density = 90% Falloff.)

For Nominal Distance, put the distance from the camera where you want the fog to be at medium density. For starters, use the inverse of the Camera Y distance, so Origin is about halfway through the fog. (Since the default Camera Position is -5 m, that would make the Nominal Distance 5 m)

Luminosity is 100%, to match the Bryce Fog. For Opacity, use 100% as well, since Bryce fog eventually reaches that level, and LightWave fog won't go past the Maximum Opacity set. Change how opaque it is close to the camera by tweaking the Nominal Distance setting.

Once again, all these values may need tweaking, but this will get you started.

Uncheck "Use Backdrop Color," and set the RGB values for Color as usual, and this part is finished, too.

Test render; LightWave vs Bryce. Click for a larger image.

At this point, I recommend adding a test ball, and rendering, to make sure that the settings are where you need them to be. You still might need to tweak the Fog (Haze) and Ground Fog (Fog) after you get the rest of your scene set up, but this should allow you to test the base settings.

(In this example, the only tweaking I did was to change the Ground Fog Top value from 400 mm to 280 mm. Note, as well, that there is a ground plane in the Bryce version, but none in the LightWave image. That's why the fog color goes unbroken to the bottom. If I were setting this up for an actual image, I'd probably tweak the Light Color a bit, to better match the Bryce image. Yeah, the color as it stands exactly matches; but in Bryce, the Sun color is modified by the Altitude. In LightWave, it's not. So, at times, tweaking is in order.)

Don't forget to enable Ray Trace Shadows, if you want cast shadows.

If you need help in Rendering, you can find some in the Beginning Rendering tutorial. Don't forget to enable Ray Trace Shadows, if you want the Sun to cast shadows in your scene. (Distant lights, like our Sun, cannot use Shadow Maps.) To do that, just go to Render > Options: Render Options and check Ray Trace Shadows in the Render Options panel that opens.

Click here to go to the next page, and learn about some special effects that aren't available in Bryce!