Forum: Carrara


Subject: Q: using transparency maps in Carrara 3

xenzeus opened this issue on Mar 31, 2004 ยท 6 posts


xenzeus posted Wed, 31 March 2004 at 2:33 AM

Anyone can share the secret of rendering with transmaps applied? (Things like hair etc.) The portions that are supposed to be fully transparent are still visible, albeit vaguely. Light through transparency doesn't seem to help.


falconperigot posted Wed, 31 March 2004 at 5:30 AM

Are you using a Multichannel Mixer shader? Have two channels for you object: one with a Transparency Value of 0; the other with a Transparency Value of 100; then put your trans map in the Blender. HTH Mark


ewinemiller posted Wed, 31 March 2004 at 6:33 AM

Q,

Two other hints. Check the No Light interactions when fully transparent option on the shader. That will keep highlights from showing up on a transparent part of the map. It's right below Bump Amplitude. Also because of the way Carrara handles transparency, you need to zero the color on the transparent spots. Color + Transparency <= 100%, so what I typically do is invert the transparency channel and use it as a multiplier on the color channel. Here's a sample shader

hairtranshader.jpg

Notice that the transparency map is used as a multiplier in the color channel and the invert color option is check in the transparency channel so they are opposite. Depending on how your map is drawn, you may have to reverse that. Also the No Light Interactions When Fully Transparent option is checked at the bottom.

Good Luck,
Eric Winemiller
Digital Carvers Guild
3D plug-ins for Carrara
http://digitalcarversguild.com

Eric Winemiller
Digital Carvers Guild
Carrara and LightWave plug-ins


ralphh posted Wed, 31 March 2004 at 12:05 PM

So checking "No light interactions when fully transparent" makes it unnecessary to use the hairtran map in the highlight and shininess channels, right? I didn't realize that's what it was for. Good to know.


nomuse posted Wed, 31 March 2004 at 12:29 PM

First Poser conversion I did, I found out the JPEG I was using for the transmapped hair wasn't quite black. I added a Shader Ops operator to turn the dark grey portions into true digital black.


xenzeus posted Mon, 05 April 2004 at 1:48 AM

Thank you very much, guys! (sorry for the late response).