Bryce 4 or greater:
Advanced Alpha Channel Tutorial
This How To is based on a question posed on the Bryce List Server:
How do you get *only* the purple "flowers" in the Spring Flowers preset to be reflective?
Enter the Materials Editor (ME) and click the Edit Materials button (1), which opens the Deep Texture Editor (DTE).
(Note: Images show end result!) In the DTE, drag the Component 2 (1) Preview to Component 1 and the Component 3 Preview to Component 2 (2). Now turn off Component 3 (3). Change the Blend Mode to "Fast Slope" (4) and turn off Color and Bump for both components (5). Don't worry about any of the colors - they don't apply to alpha channels.
Open the Noise and Filter Windows by clicking the buttons (1) at the bottom of the DTE.
First, make sure the Component Indicator (blue dot) is in the first slot (1). Change Component 1's Filter Type pop-up from "Clip" to "Abs" (2). Now change the "a" value to around -1. 9 and the "b" value very close to +1 (3). To increase the area of reflectivity, increase (towards zero) the "a" value.
Click the Component Indicator over to the second slot to select Component 2 (1). Now click the green "Edit Noise" button (2). Change the Noise to: Type=Sine, Mode= Standard and Octaves=0 (3) and click the check mark to save the changes. Now change the Filter to "Clip" (4) and dial down the "a" and "b" (5) values until the Filter Display is a flat line along the bottom and the preview is all black (as shown).
At this point your combination preview should look something like this image. Click the Texture Library Button (1) and save the texture as something like "purpalpha". Now click the DTE "X" button, not the OK Check Mark! (2). If you forget, just reload the original preset and continue from here.
Back in the ME, click the Reflection Dot (1) over to the second column and a random texture appears right below the original.
Click the Texture Preset button for the new component (1) and select the alpha texture you created above. Now click the Mapping Mode button (2) and make sure it matches the first component (in this case "World Space"). Now click it again and select "Alpha Scaling" (3) Note: The pop-up menu has been shortend in this image, it's down at the very bottom.
Be sure the the second component has the same frequency as the first (it usually does) by clicking the Edit Texture button (1) then clicking on the numbers (2) and changing them to match the first (A). You can compare the two with the gold A and B buttons (3).
Now dial up a high Reflection value (1). Because we enabled "Alpha Scaling" the slider conrols how much reflectivity is produced - with 0 being none and 100 being Max. Now exit the ME and Render. If you want to change the area size, go back to step 5 (only) and change the "a" and "b" values. Note: pure white is 100% reflectivity and black is 0%.
Download the Texture (26K PKZip File)
Download this tutorial as HTML (119K PKZip File)
