[osg-users] [osgPlugins] png plugin - problem loading images

[Andrey Ibe]

Hello good ppl!

i am quite new to OSG, though i managed to build it from source with several plugins. now one of them is not working - PNG. and i do need it.

i am using MinGW gcc compiler suite and w7/x64 system.

i built osg 3.xy from sources, with libpng, zlib, libjpg and coin plugins, which i also built from sources.

i have a model that is supposed to load .png files as textures, but i'm getting this message with all the files

Code:
Warning: Could not find plugin to read objects from file ".\textures\13.png".

[Arrow] i tried renaming the png file to some nonsense and the program screamed that the file does not exist - so i guess the file path in the model is all right.
[Arrow] i also tried putting the folder with osg plugins into the system path, as suggested in one of the threads.
[Arrow] then i tried renaming the texture to load in the model then saving the texture into .jpg file - it worked. so the plugins themselves DO work.
so where is or can the prblem be? [Question] why does the plugin not work? [Question]
i do have mingw_osgdb_png.dll in the plugins folder, which is accessible from the console i run my applcation, or the osgviewer program.
you may ask why do i need png textures when i am able to use .jpg textures - the answer is easy - i need transparent textures.

Thank you for your time!

Cheers,
Andrey [/code]

------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=44012#44012

_______________________________________________
osg-users mailing list
osg-...@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

[Laurens Voerman]

Hi Andrey,

Most likely your osgdb_png.dll depens on a dll not in your path. It might be libpng.dll but now I am just guessing.
use dependencywalker (http://www.dependencywalker.com/) to see what's the problem.

Laurens.

[Andrey Ibe]

thank you for the tip. i tried locating the libpng library and i found there was a file libpng15.dll in the system path. i don't really know how this library file-name-thing really works so i renamed it to "libpng.dll" and tried running my osg app again, but without any success.

i will try the program you suggested shortly and report the result, though i have all the libraries that i needed to compile the libpng and the osg in the system path variable.

Andrey

------------------
Read this topic online here:

http://forum.openscenegraph.org/viewtopic.php?p=44139#44139

[Laurens Voerman]

Hi Andrey,

Just assuming the libpng15.dll is the one you build from source, and not
something you happened to have in your path..
renaming the way you did is not very likely to work, an executable
should now the name of the dll it wants to use, and will fail to start
if you renamed it.
However, the libpng15.dll itself tends to depend on libz.dll (or
libz1.dll) - the one you build. that should also be in your path.

Laurens.

[Andrey Ibe]

hi laurence!

i have got zlib1.dll in my path env.. it is the one i used for building the libpng15.dll dynamic library. both libs i used to build the OSG.

i kept every single dynamic library i built during the process of compiling the osg in my compiler's bin folder, which is in my system PATH env. the same way i kept static libs in the libs dir and include files in the compiler's include dir.

again i tried the trick with renaming (i also kept a copy with the original name) with no difference in the app's behaviour.

------------------
Read this topic online here:

http://forum.openscenegraph.org/viewtopic.php?p=44163#44163

[Filip Arlet]

Hi,
You are saying that you built OSG from sources. Are you completely sure that you set up PNG_LIBRARY and PNG_PNG_INCLUDE_DIR ?
Because if you don't, osg_png plugin won't compile.

Cheers,
Filip

------------------
Read this topic online here:

http://forum.openscenegraph.org/viewtopic.php?p=44180#44180