Unsupported — We cannot guarantee that this software will work properly on Mac OS 10.8 and above. Please be careful.

Release: GL Tools, v20071214

Release Type: Beta
Version: 20071214
Release Notes

This GL Tools beta adds the Depth Buffer Alpha Threshold Patch.

This new patch causes rendering subpatches to not write to the depth buffer when writing transparent pixels below a specified threshold. This helps achieve better depth sorting with existing GL patches.

Feature suggested by CoreMelt.

You may get a "halo" of pixels near the transition; there's nothing we can really do about this that I'm aware of.

This plugin is also smaller than the previous version: Apparently "Clean All" in XCode doesn't really mean "delete all intermediate build results", so some stale unused stuff was in the previous version that had accumulated due to some testing...

GLTools-20071214.zip119.72 KB

cwright's picture
The picture

To explain the picture a bit, there's a GL Point in the background, with 4 sprites in front (textured by a yanomano composition), all layered earlier than the gl point. The sprites are set to "Read/Write" Depth Testing, which causes the 'transparent' box around the ones on the right (which are not in the Threshold patch). The ones on the left, however, do not draw such boxes, which is the expected behaviour.

amos's picture

The depth buffer alpha threshold patch is really useful!

I was working on a composition today that involves moving sprites with transparency intersecting each other. This patch allows things to look much better.



Installation Instructions

Place the plugin file in
/Users/[you]/Library/Graphics/Quartz Composer Patches/
(Create the folder if it doesn't already exist.)

A set of patches for drawing GL primitives and modifying the GL environment.

Source code is available on GitHub.


Logo by @usefuldesign.au.

Known issues

  • The GL Field of View patch doesn't work properly on Mac OS 10.9 (it produces stretched output).