I definitely think your correct that DXT1 should be used for --compressed. I think the best might be to be able to specify dxt1a as a compression format from the command line. This isn't accepted at the moment but I will look into adding it. I have also found a bug which mean the destination imagery only contains alpha values of 1 when either dxt3 or 5 is chosen. I have fixed this locally and will submit my change soon.
Thanks for the nvvt implementation by the way. It is great work. One less thing on my to-do list now : ) From: [email protected] [mailto:[email protected]] On Behalf Of Fabien Lavignotte Sent: Monday, 11 October 2010 5:01 PM To: OpenSceneGraph Submissions Subject: Re: [osg-submissions] [vpb] Bug fix with NVTT I think it is a little weird to use DXT1 with --RGBA-compressed (so 1bit alpha as you said), and to use DXT3 with --compressed (double the size of the texture to handle alpha channel). Now we will see what Robert thinks about it :) Fabien ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Christiansen, Brad Sent: lundi 11 octobre 2010 10:31 To: OpenSceneGraph Submissions Subject: Re: [osg-submissions] [vpb] Bug fix with NVTT Hi, I am not 100% sure it was an error to use DXT1 for RGBA. The code on line 260 of TextureUtils.cpp setups up handling of RGBA textures using nvtt ;;Format_DXT1a. >From my reading, you can use DXT1 with an alpha channel but the alpha is only >a 1 bit value. This might not work in many cases but I would guess that alpha >is used in output textures from VPB mostly for textures on the boundary of the >source data where only some of the texture contains data (if that makes >sense). That is certainly how my terrains use alpha and I would like to use >this option (DTX1a for my output of RGBA textures). Another quick question: if --RGBA-compressed (OpenGL compression) is passed to osgdem / vpbmaster, what format will the nvtt code path use? Is this simply not supported? That is my reading of the source. Cheers, Brad ps- I am testing your changes now. Thanks again. From: [email protected] [mailto:[email protected]] On Behalf Of Fabien Lavignotte Sent: Monday, 11 October 2010 4:07 PM To: [email protected] Subject: [osg-submissions] [vpb] Bug fix with NVTT Hi Robert, As seen by Brad, the code with nvtt does not works correctly when using --terrain. So here is the fix in TextureUtils.cpp. I also swapped the compression used with BuildOptions::COMPRESSED_TEXTURE and BuildOptions::COMPRESSED_RGBA_TEXTURE. It dit not seems correct to use DXT1 for RGBA, i think it was just a copy/paste error. Cheers, Fabien ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ DISCLAIMER:--------------------------------------------------------------------------- This e-mail transmission and any documents, files and previous e-mail messages attached to it are private and confidential. They may contain proprietary or copyright material or information that is subject to legal professional privilege. They are for the use of the intended recipient only. Any unauthorised viewing, use, disclosure, copying, alteration, storage or distribution of, or reliance on, this message is strictly prohibited. No part may be reproduced, adapted or transmitted without the written permission of the owner. If you have received this transmission in error, or are not an authorised recipient, please immediately notify the sender by return email, delete this message and all copies from your e-mail system, and destroy any printed copies. Receipt by anyone other than the intended recipient should not be deemed a waiver of any privilege or protection. Thales Australia does not warrant or represent that this e-mail or any documents, files and previous e-mail messages attached are error or virus free. -------------------------------------------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ DISCLAIMER:--------------------------------------------------------------------------- This e-mail transmission and any documents, files and previous e-mail messages attached to it are private and confidential. They may contain proprietary or copyright material or information that is subject to legal professional privilege. They are for the use of the intended recipient only. Any unauthorised viewing, use, disclosure, copying, alteration, storage or distribution of, or reliance on, this message is strictly prohibited. No part may be reproduced, adapted or transmitted without the written permission of the owner. If you have received this transmission in error, or are not an authorised recipient, please immediately notify the sender by return email, delete this message and all copies from your e-mail system, and destroy any printed copies. Receipt by anyone other than the intended recipient should not be deemed a waiver of any privilege or protection. Thales Australia does not warrant or represent that this e-mail or any documents, files and previous e-mail messages attached are error or virus free. --------------------------------------------------------------------------------------
_______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
