Build a skybox in Bryce

Learn to build a three dimensional background element for your scenes. This tutorial demonstrates how to export your Bryce scene as a series of images for building a skybox and offers additional tips and advise on building and integrating it into your work flow.

A skybox is essentially a fill in the blanks background element that is wrapped around your scene in 3d space so that regardless of where you look, there is always some kind of visual imagery to look at rather than blank space at the end of a flat background.

Skyboxes are typically used to define the outermost background element in a scene, in particular skies (hence the name). They may also contain some terrain details and ground elements, but are not limited to just skies, a skybox can also be used to create and entire rooms, or hallways, or any other environmental element where your character may find themselves inside of.

However, their purpose is not so much to create a three dimensional look but rather to produce an illusion of environmental depth and give your “worlds” a certain felling of greatness and expansiveness no matter how stylistic the actual artwork may be.

Bryce by default does not allow you to directly export a skybox texture, but with a little soft work we can easily manipulate the software into giving us the 6 images required to put together a skybox ourselves.

The secret to getting the images we need so that they align themselves seamlessly to each other, is to export the images from Bryce at exact 90 degree angle increments.

First of all lets begin by going to the document setup option from the file menu.

And here we will set up the document itself to a squared 1:1 aspect ratio. For my needs I will choose a 720×720 document size, depending on your monitor you may want to choose something smaller, it really doesnt matter that much at this point. What does matter is the export size. You need to be able to export images large enough that when enlarged or re-sized they wont degrade or become pixelated as easily so the larger the better.

The side effect of course is that the larger the resolution the longer it will take to render each image. In this case I’m going to go with a 1440×1440 resolution but if you can afford to go larger, go for it. And of course if you are just doing this right now for the sake of experimentation or learning how to do it, I would suggest sticking to a low resolution for speed purposes, since in such case the image quality itself is not that important. You can always come back and “up” the resolution later when you are ready to export the final images to be used in an actual production.

Next we will go into the “Sky and Fog” section and make sure we remove the “Link Sun to View” option. This will help us maintain a more seamless lighting situation across all 6 images.

Next we switch to camera view by clicking on the “perspective toggle” control. The little director chairs icon on the upper left hand side of the document window toggles into an icon that looks like a little camera. We can now move around as if were seeing the environment from the point of view of the camera.

Bring up the camera settings by double-clicking on the trackball. And in the settings panel we reset our cameras rotation to x:0 y:0 and z:0 and adjust the camera’s field of view setting to 112.5 degrees.

Since this is our default straight ahead view, we will refer to it from now on as our “North” view. There will be 6 views in all we need to account each of the sides in a cube.

A great little time saver is to make use of the “saved views controls” on the upper left hand side of the Byuce user interface. Clicking on one of these buttons will save your current view to it. So its a good idea to go through all your camera views and save them to one of these buttons before going about the actual rendeing process.

Then you can just render each view by toggling through of the views using those buttons. Furthermore if you save your Bryce file, your views are also save so you can use it as a starting point the next time you need to put together a skybox.

Here are the settings for eah of your 6 views:

Once your images are exported you are then ready to assemble your skybox. For example, if you use Ater Effects you could simply import the 6 images and assemble them as a cube within AE’s 3d environment. Link the images together so that you can move them around and manipulate them as a single cube object. You then just use this cube to wrap around your entire scene in AE.

The most common approach however is to use them inside a 3d cgi environment like Maya, Max, or even Poser. You can map each image to each individual side of a cube, but here is the kicker, you have to invert normals for the cube. This is basically flipping the cube inside out so that rather than seeing the outside of the cube, you see the insides. And the texture mapping is applied to the interior of the cube rather than the outside.

The image below demonstrates the full map, as you can see once it’s wrapped around a cube it basically gives the illusion of being inside a complete three dimensional environment.

Other similar object along the same lines as a sky-box are the Sky-dome which is half a sphere usually includes just the sky and horizon, and a sky-sphere which is a whole sphere mapping the entire area in pretty much the same way the cube does.

Lastly, you can use a texture map such as the one above as a 2d template for drawing and painting your own hand painted backgrounds to better suit your projects style, and you would end up with a seamless hand painted background that wraps itself all around your characters and scene elements in such a way that you will end up with the versatility of a CG environment with the look and feel of a traditionally hand painted background.