Fractal Terrains in Bryce 2

By Steve Lareau
Hilltop Design

This tutorial is on how you can turn a fractal into a terrain in Bryce from Metatools, although this concept can be applied to most other graphics programs. I'm assuming that you've already spent time tinkering with Bryce, and if this is the case, this should be a snap. (By the way- this tutorial was created in Bryce 2 for Windows; this will work in Bryce 3D as well, you'll just have to adjust to the different interface.) I've included everything in this tutorial- the images found here, as well as the scene file I used for this tutorial in a ZIP file which you can open up in Bryce 2 and Bryce 3D so you can study it. Scroll to the bottom of this page and start your downloads, then come back here and start doing some reading. Before we do anything else, let's take a look at the basics of what we're working with, shall we?


The original fractal

The original fractal.

The image above is a fractal I created, which I thought would look cool as a terrain. It's got all sorts of weird convolutions and spirals which should translate into something interesting when it's rendered out in 3D. You have to look at the image above the way that Bryce will look at it as a terrain. When you import an image into the terrain editor, Bryce turns an image into varying shades of gray, and anything that is light in color will be "high", and anything dark will be "low". Lets look at a potential problem with this image; on the sides of the image you see a turquoise indentation on all the sides, followed by a purple-blue indentation, then another purple band in the middle of it. There will be a "step" in the height where these three colors are if we leave it the way it is. Open this image up in PhotoShop or your favorite image editing program and try a few things. You can use your blur tool and smooth and blend these areas, which will make it a more gradual "gradient ramp" when it's imported. Or, since I'm more interested in the circular areas of the image, I want to get rid of anything that's not going to give me something to work with as far as height.


The doctored fractal

Fractal that has been cleaned up.

What I've done with the image above was simple- I opened the image up in PhotoShop, and selected a part of the turquoise area with the magic lasso tool, with the tolerance set to zero. I then went to menu bar and hit SELECT, then SIMILAR, which selected all 4 of the turquoise indentations. Use your fill bucket and pour the color black into each of these areas. Go through the same steps outlined above for the other problem colors. When you're all done, you should end up with an image that looks exactly like the one above. You can also hit the entire image with a gaussian blur with a radius of 0.5 pixels just to make things blend a little bit better. Save this image with a name that will make sense to you later.


Grayscale fractal

Grayscale version of the fractal.

Now, convert the image you just modified into a grayscale for importing into Bryce's terrain editor. It's not really necessary, but do it so you can study how Bryce will read the information you're feeding it. Save what you've got on the screen after converting it to grayscale with a name that designates that it's a grayscale. I've already done that as you can see in the image above. The black areas will all be the lowest level of the 3D terrain, and everything that is white will be height. The thing that's more apparent when you see this image in grayscale is that each of the "cones" in the corners will have some really cool looking "ribs" on them when it's imported as a terrain.


The terrain editor

Start Bryce, and go to EDIT, and create a terrain by clicking the mountain. Click on the wireframe mountain to select it, then hit the E next to it for EDIT , then you'll see the terrain editor screen as shown below. Click the tab for PICTURES and you'll see something like below.

The first thing we need to do is set the grid resolution to the same size as our image, which in this instance is 512 by 512 pixels in size. Click the little grid as shown with step 1 above, and check 512 as shown. As illustrated with step 2 above, hit LOAD and select your grayscale image. It'll be in the first box as you can see here. Grab the little button to blend as shown as step 3, and drag it to the side until the third box looks like the first box. Look good? Cool- hit APPLY as shown in step 4, and your 3D preview terrain at the lower left should look like you see it above. If you'd like, you can go into the ELEVATION area by hitting the elevation tab and smooth it out. If you're happy with the way this looks so far, click the checkmark as shown in step 5 and exit this area.


The materials composer

Next to the wireframe of the terrain, hit the M button for MATERIALS. This will pop up the window as shown below.

What we're about to do is to take our original fractal and plop it on top of the terrain you just created. As shown in step 1 above, we're going to turn channel A into a 2D texture by clicking the little arrow at the top as shown, and simply select 2D texture, which Bryce calls "Leo". It'll show a gold picture of Leonardo in the window. Click on the first square in that area and the window below will pop up.

Click LOAD as shown as step 1 above, select your colored (the cleaned up version) fractal, and it'll load into the first window. Now, as shown at step 2, click COPY, then click PASTE as shown in step 3. If the third window looks like the one above, click the check mark as shown as step 4 and close this window- you're done here!


Back to Materials Composer

Click on the arrow as shown in step 2 in the picture below and select OBJECT TOP. What you've done is mapped the colored fractal to sit on top of the terrain. The channel with the texture is channel A. If you look at the A channel at step 3, you'll notice that some blue slider balls are in the default position, and others have been dragged into the A channel slot. Basically, when you drag a slider ball into different channels, the texture in that particular channel will affect the properties of the material. So go ahead and drag the ball for DIFFUSE COLOR, AMBIENT COLOR, and SPECULAR COLOR into the A channel. You can go back and experiment with the other settings another time, but let's get this scene ready to render. Now, to get the scale of the fractal to match the terrain perfectly, at step 3, you have to set the red bar sticking up above channel A to zero. Either click on the letter A and type in 0 (zero) , or just drag that red bar all the way down. Go ahead and set the other options like diffusion and so forth like I have them set here. When you're done with the settings, click on the arrow as shown at step 4 and exit back to the wireframe screen. Note- the preview window in the upper left hand corner won't display things exactly like it will once it's rendered. You're all done, now go to the main screen and render the example!


DOWNLOADS

To download the Bryce scene file in ZIP format that was used to create this tutorial, click HERE. 610 kb
(The scene is both MAC AND PC compatible)

To download all the fractal images used here, click for the ZIP file.
PC VERSION 1,225kb
MAC VERSION 884 kb

Mac users can get a PKZIP compatible decompression program by clicking on the link below! ftp://ftp.inland.net/pub/apps/utils/mac/zipit/zipit.hqx

To see some more examples of Bryce Fractals, head over to my main website.


LINKS TO FRACTAL GENERATING PROGRAMS

Flarium, a Windows based Fractal generating program.
(This one is perfect for creating fractals for use as terrains for Bryce, since you can scale the fractal to match the size of the terrain resolution before you render it!) Make sure to download all the additional formulas there too!

Link to Fractint, a DOS based Fractal generating program.
This one has a ton of presets to get you started.