Transparency Tutorial

When you import a Michael into Bryce from a Wavefront OBJ file all transparency map information is lost. You have two options, either select the objects and set their Hidden attribute (or delete them entirely) or create a new material to map the objects correctly. The first option is ok if your scene doesn't include a close-up view but taking a few minutes to map these objects can enhance the realism of your finished image. In this tutorial we'll concentrate on mapping Michael's eyebrows and eyelashes.

Selecting Objects

If you imported directly from Poser, you'll have to figure out which objects to select. If you post-processed the file with Grouper you'll find that it added descriptive names. If you use the Mac platform and can't use Grouper, you'll have to fish around to get the proper objects selected.

Without Grouper

With Grouper

head_1, head_2 and head_7

FigureX_3, FigureX_4 and FigureX_9

Eyebrows and/or Eyelashes

Once you've got the objects selected, group and name them to make it easier to select them later. The material selection palette in Bryce can be a real time saver for this part.

Setting Up Transparency Materials

Once you've got the objects selected, open the Materials Lab and make the following changes:

Drop down the Material Options menu and select Blend Transparency.
Set the Diffusion to 100, Ambience and Specularity to 0.
Assign Transparency to one of the material channels. I used the D channel here so you could see everything in one screen shot.
Set the Transparency to 15.
Click on the P to change to an image mapped texture.

When you've finished, click on the pink dot above the P to open the picture room.

In the Picture Room, make these changes.

Click on one of the blank grey panels and a file open dialog appears. Find your transparency map and click Open. Here I used the file called MMHeadTR.jpg that came with Michael.
Click Copy under the left picture, then Paste under the center picture. Click Delete to confirm the copy. This copies the image to the alpha channel.
Click the black circle over the left color channel and confirm by clicking Delete at the dialog.

You should see something like this when you're finished. Click on the check mark to close the Picture Room and again on the checkmark to close the Materials Lab.

Adjusting Transparency Maps

With the material setup, you're ready to try a test render. If the result isn't what you expected, there are two parameters you may want to change.

Diffuse color
In the Materials Lab, Click or Alt-Click on the circle to the right of the word Diffuse. This will open the color dialog. You can change the color value of the transparency map here. The diffuse color is read from the Wavefront OBJ file so you should see the same color in Bryce that you did in Poser.
Transparency
Adjust this value to control the strength of the map. Higher numbers make the map more transparent, lower numbers make it more visible. Start with a value between 15 and 25.

You can see the effect of changing the Transparency value below.

Zygote's Map


Transparency 0%	Transparency 10%	Transparency 20%	Transparency 30%

Transparency 40%	Transparency 50%	Transparency 75%	Transparency 100%

Kim's Map (The Karmic Newt)


Transparency 0%	Transparency 10%	Transparency 20%	Transparency 30%

Transparency 40%	Transparency 50%	Transparency 75%	Transparency 100%
This map is available from www.renderosity.com, search the Poser Free Stuff section for the keyword Michael. The author chose not to include her contact info so we'll just think of her fondly as she requested.

Notice that in the two maps the relative strength of the eyebrows and eyelashes is different. If you don't like the balance between the two simply create two materials and adjust the Transparency values independently.

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