It's a material property, not a light property, yet Refraction in Bryce 5 can be used to dramatically change and enhance the way Bryce 5 lighting works in some enclosed environments. It can take an image that is flat and lifeless and give it depth and mystery.

The Bryce 5 manual describes refraction as "As a light wave passes from air through another medium such as water or thick glass, it seems to bend or turn to a certain degree." The manual approaches refraction as it can be used with transparent objects to simulate water or glass. It is very powerful for this purpose. But I've taken it a step further. I asked, "What if I were inside the "other medium", then what would refraction do?"

In this tutorial we will find out! We will alter the model we made in Artificial Lighting and apply refraction to our environment to see how this amazing property works in conjunction with lighting for scene development in Bryce 5.

NOTE: Bryce 5 refraction within an object (i.e. cube, sphere, torus, cylinder) works on Bryce 5 primitives. However, it does not work inside a mesh object.

Note: We'll do a LOT by the numbers. I always indicate negative numbers in RED INK.

Expanding the Scene:

Open the model used in the previous section: Ambient Light.

Click on the room object and open the Attributes box.

Change the settings as follows:

Position:

X = 0, Y = 48.1, Z = 212

Size:

X = 144, Y = 96, Z = 630

This makes the room much larger, like a corridor. We are sizing it like this to get a better view of what Refraction does. It would have an effect if we had not changed the size, but it would have been much more subtle because of the lack of depth.

Duplicate the Ceiling Fixture:

Select the domelight object (our ceiling fixture) and duplicate it (Control-D in Windows, Command-D in Macintosh). Then open the Attributes box.

Change the settings as follows:

Position:

X = 0, Y = 96, Z = 225

This gives us a second light fixture object located further down the corridor so we can see it affected by Refraction. You can name it domelight 2, or allow Bryce 5 to name it for you based on its previous name.

Duplicate the Radial Light:

Select the radial light object (light) object and duplicate it (Control-D in Windows, Command-D in Macintosh). Then open the Attributes box.

Change the settings as follows:

Position:

X = 0, Y = 48, Z = 225

This gives us a second light source that we can observe as we apply different refraction values. You can name it Light 2, or allow Bryce 5 to name it for you based on its previous name.

Setting the Sun:

We want to see the effect of Refraction on depth, so lets set up our ambient light from the Sun so we can clearly see what happens at the far end of our corridor.

Enter the Sky Lab and change the Sun Controls as follows:

Azimuth = 180

Altitude = 30

This puts the Sun behind us and above us so its light is bouncing off the fall end wall and the floor of our scene. We did not change the radial light settings from our previous values of Intensity = 10, Range = 80.

However, if you did change these settings, select both radial lights and change them to Intensity = 10, Range = 80.

Your scene should look like the image in the NANO preview at the left.

Changing the Lighting in our Scene:
Falloff = None

None: The intensity of the light stays the same regardless of the distance it travels.

Before we play with Refraction, lets see our scene at different light settings, just to refresh ourselves and see what they look like.

Select both radial lights and enter the Light Lab. When both lights are selected, the Light Lab settings will apply to them both.

Intensity = 2 and select Falloff None

I rendered my scene, but you could simply check it out in the NANO preview of the Light Lab. It should look like the image in this table. Notice the compound shadows from the objects. That's because both radial light sources have Cast Shadows turned ON. You could turn off Cast Shadows for either one of the radial lights to eliminate one set of shadows. If you turn off Cast Shadows for the Light 1 (the light closest to the camera), the darker shadows close to the objects will not show and the longer, fainter shadows from Light 2 will remain.

Pay close attention to the ceiling light fixtures we created as you change settings. You'll see that the settings alter their appearance thanks to shadows.

Although we have only two lights in our scene, Bryce 5 lighting is so powerful that we can dramatically change the look just in the Sky Lab alone! To keep from bombarding you with every possiblity, I'll just suggest settings to change in the Sky Lab:

Change Azimuth and Altitude settings for the Sun and watch how this changes your scene.

Change the Ambient value using the grayscale levels in the color palette. You could also try some color settings and see what happens.

Change the Sky Dome value using the grayscale levels in the color palette. You could also try some color settings and see what happens.

Change the amount of Sky Shadows allowed. We have been using 50, but watch what happens when you change this.

Combine all the above. As you will discover, the Tutorial section on Sun and Moon light has helped us understand how to use this amazing ambient light source provided by Bryce 5.

NOTE: You may find yourself playing with these settings for quite some time. The flexibility of Bryce 5 lighting is an open invitation to imagination, curiosity and discovery! When you are done experimenting, restore the values to the way they were at the start of this Falloff None experiment.

Changing the Lighting in our Scene:
Falloff = Linear

Linear: The light gradually dissipates as it travels away from its source. This is the default in Bryce 5.

Make sure both radial lights are selected and enter the Light Lab. Set the following:

Intensity = 25 and select Falloff Linear

This is the Bryce 5 default. Your scene should look like the one at the left.

We know about the different Falloffs for lights, so now it's time to play with them!

In addition to the overall effects we can change thanks to Bryce 5's powerful ambient lighting, with two artificial light sources, we can now get even more interesting effects and changes by manipulating the radial lights independently. Here are some suggestions:

Change Light 1 from Falloff Linear to Falloff None and adjust the Intensity value. But keep Light 2 at Falloff Linear.

Change Light 2 from Falloff Linear to Falloff None and adjust the Intensity value. But keep Light 1 at Falloff Linear.

Play with Cast Shadows On or Off for either light in either situation above.

Change settings in the Sky Lab for ambient lighting while giving the radial lights different falloffs.

As you can see, the more we understand about the WAY light works in Bryce 5, the more options we have to play with and adjust! How you feel about the results is a matter of your own personal perception and taste, but I am sure you'll find that this incredible flexibility of lighting in Bryce 5 is now something you WANT to take advantage of. And it's fun to experiment, isn't it!

Changing the Lighting in our Scene:
Falloff = Squared

Squared: The light dissipates rapidly as it gets farther away from its source.

Make sure both radial lights are selected and enter the Light Lab. Set the following:

Intensity = 150 and select Falloff Squared

Your scene should look like the one at the left.

Just as in the previous experiments, you should play with different settings for the lights independently and see what happens And don't forget to play with ambient light too!

TIP: We are using just two radial lights. One is farther away than the other. Although we are using the same settings for both, if you think about how light is energy, and energy dissipates over distance, it may "dawn" on you (pun intended) that the light that is farther away could actually be given a lower intensity value to increase the feeling of depth! Try and it and see what you think.

Changing the Lighting in our Scene:
Falloff = Ranged

Ranged: The light dissipates rapidly after it travels the distance indicated by the range modifier.

Make sure both radial lights are selected and enter the Light Lab. Set the following:

Intensity = 10 and select Falloff Ranged, Value = 80

Your scene should look like the one at the left.

We are back to where we started and ready to play with a new feature, the material settings for Refraction. I'm using the Ranged Falloff method to help you see how the Refraction affects a scene. You should also try these experiments with the other radial light Falloffs.

Changing the Lighting in our Scene:
Material Refraction: Air

When you are inside a Bryce 5 primitive, you can change the Material Property Refraction to alter shadows and depth perception.

Select the room object and click on the M to enter the Materials Lab.

Refraction is in the OPTICS section. Bryce 5 will generally set a Refraction value for a simple color to 100, or the refraction in Air.

According to the Bryce 5 manual, refraction settings between 0 zero (0) and 100 do not bend light. So we can start playing with Refraction from a value of 100 or Air. Bryce 5 will display the material name (usually) for different known refractive values.

You have to render your scene to see the effects of refraction. When you render your scene with the settings here, it should look like the image at the left.

Look down the corridor. Light is progressing unhindered and there is not much feeling of depth. Because we set the Sun's azimuth to 180 and altitude to 30, we can see a lighter floor and far end wall. We want that so we can see what refraction inside an object can do for us.

Changing the Lighting in our Scene:
Material Refraction: Water

Select the room object and click on the M to enter the Materials Lab.

Set the refraction value to 130

According to the Bryce 5 manual, a refraction setting of 130 represents Water. However, in my version of the program, the OPTICS section doesn't display the word WATER when I use this value.

Render your scene and you'll see that things are getting considerably darker overall. All ow that to happen for now. Higher refraction values will tend to darken a scene when used in this method.

Changing the Lighting in our Scene:
Material Refraction: Glass

Select the room object and click on the M to enter the Materials Lab.

Set the refraction value to 153

According to the Bryce 5 manual, a refraction setting of 153 represents Glass.

Render your scene and you'll see that the farther end of the scene is getting darker, but the closer end is not getting as dark. At this point, the refraction is beginning to give us some sense of depth. You may also notice by comparing the images that the hot spot of the lights are becoming slightly softer.

Changing the Lighting in our Scene:
Material Refraction Increase

Select the room object and click on the M to enter the Materials Lab.

Set the refraction value to 170

Our refraction value doesn't represent a specific material but we're using it because we want to look at the far end wall. Even though the Sun is trying to illuminate it, the refraction is countering the effect. We can still see it, but it has little definition.

Changing the Lighting in our Scene:
Material Refraction: Crystal

Select the room object and click on the M to enter the Materials Lab.

Set the refraction value to 190

According to the Bryce 5 manual, a refraction setting of 190 represents Crystal.

Render your scene and you'll see that the farther end of the scene is now in shadow. Although the entire scene is dark, it has developed a "mood". We get the feeling that this corridor might be quite long. Our objects are a bit dark, so here's a tip to fix that.

Select an object and enter the Materials Lab. Set the object's AMBIENT color to match its DIFFUSION color. Then increase the AMBIENCE value to 50.

Do this with each object. Now the objects are brighter, but no extra lighting was required to get the effect!

EXPERIMENT! Now that you can see how Refraction can dramatically change and interior scene, try different lighting Falloffs and different General Ambient light settings in the Sky Lab.

Changing the Lighting in our Scene:
Material Refraction Maximum

Select the room object and click on the M to enter the Materials Lab.

Set the refraction value to 300

Our refraction value doesn't represent a specific material but we're using it because we want to look at maximum refraction.

If you like to play computer games like the MYST series and have see images with dramatic and atmospheric room lighting, this is partially how it is done, by changing the refraction of the environment.

In Conclusion:

For an interior scene that is seen from inside an object, the material property, Refraction, can make a big difference in creating atmospheric effects. In general refraction will darken a scene especially in the distance. Use of refraction can greatly enhance the drama of an interior scene without increasing rendering times or the use of additional light sources. It is a very useful tool.

Bryce will apply Refraction to primitive objects, but not to mesh or terrain objects. There's a way around this, but that's the subject for a future tutorial!

Refraction works in conjunction with ambient and artificial lighting. All the parameters of these light sources can be manipulated with refraction to get some spectacular results!