The Exploits of Plouj

This is documentation of how I used Yukon and Seom to video capture a Google Earth trip for a recent video project in Fedora 10. I used the official installation guide as a starting point.

Compile the Seom library

I choose to install both Seom and Yukon in a custom prefix /home/plouj/yukon, rather than the system wide /usr or /usr/local.

$ svn co https://devel.neopsis.com/svn/seom/branches/packetized-stream seom
$ cd seom
$ ./configure --prefix=/home/plouj/yukon --arch="x86" --cflags="-W -Wall" && \
make CC="gcc -m32" && make install LIBDIR="lib"

Note that “–arch=”x86″ and “-m32″ are only necessary for me because my operating system is 64bit and I need 32bit versions of seom and yukon (to work with 32bit Google Earth).

Compile and install Yukon

$ svn co https://devel.neopsis.com/svn/yukon/branches/rewrite yukon
$ cd yukon
$ ./configure --prefix=/home/plouj/yukon/ --libdir="lib" --arch="x86" && \
make CC="gcc -L/home/plouj/yukon/lib -I/home/plouj/yukon/include -m32" && \
make install

Install Google Earth for Linux

Obviously get it here: http://earth.google.com/

Modify the Google Earth startup script

Since I chose /home/plouj/bin/ as the “Binary path” for Google Earth I was editing /home/plouj/bin/googleearth. All I had to do was to add yukon/seom library and executable paths at the end of the script:

...
cd "${GOOGLEEARTH_DATA_PATH}/"
LD_LIBRARY_PATH=/home/plouj/yukon/lib/:$LD_LIBRARY_PATH \
PATH=/home/plouj/yukon/bin:$PATH exec yukon "./googleearth-bin" "$@"

instead of the original:

cd "${GOOGLEEARTH_DATA_PATH}/"
exec "./googleearth-bin" "$@"

Capture

Finally, the capture process is well documented on the Yukon website.

Blender sequencer gives the ability to optimize rendering of repeated frames by keeping the first result in memory cache and re-using it. Depending on the project, it might be necessary to increase this limit beyond the default 32MB. If the limit is surpassed while rendering a single frame, Blender clears the cache before proceeding to the next frame and the re-renders everything from scratch.

Increasing the cache limit is easy to do in the UI:

This setting is stored in the user’s preference file (~/.B.blend on Linux systems) and, therefore, applies to all projects. However, rendering from the command line requires using the -b argument, which explicitly ignores the user’s preference file. Apart from editing and re-compiling the Blender source code, I found only one way to increase the memory cache limit.

The trick is to use a Python script, like below, to change the user preferences before rendering the scene:

import sys
import bpy

def main():
	bpy.config.sequenceMemCacheLimit=4096

if __name__ == '__main__':
	main()

Add the script to the command line like this:

./bin/blender -b sample-static-text.blend -P render_settings.py -a

Note that the order of arguments matters because first we need to load the scene (with -b), then change settings through Pythons (using the -P option) and finally render the animation (with -a). Also, you need at least version 2.49a of Blender for this to work.

For reference, here’s is the the source file which hardcodes the 32MB limit:

intern/memutil/intern/MEM_CacheLimiterC-Api.cpp:

...
static intptr_t & get_max()
{
        static intptr_t m = 32*1024*1024;
        return m;
}
...

Introduction

In this post I’ll document the steps I had to take to build DXX-Rebirth (a modernized Descent game engine) for Windows using MSYS and MinGW.

MinGW, MSYS

From  Pantokrator’s blog:

• install MinGW
  • choose a lowercase install path: c:\mingw
  • choose to download and install current version
  • enable g++ (for physfs)
• install MSYS
• install msysDTK

SDL and SDL_mixer

Also from  Pantokrator’s blog:

• download the SDL source
• in the MSYS shell, compile it with

./configure --prefix=/mingw && make && make install

• download the SDL_mixer source and in a MSYS shell, build it with the same command:

./configure --prefix=/mingw && make && make install

PhysicsFS

• Download the physfs 1.1.0 source.

• Compile with the same command again:

./configure --prefix=/mingw && make && make install

SCons and Python

From Globulation2 MinGW instructions:

• install Python 2.6
• install SCons
• add:

PATH=$PATH:/c/Python26:/c/Python26/Scripts

• to the end of /etc/profile in MSYS so that SCons can run from the MSYS shell.

Subversion

• install TortoiseSVN

DXX-Rebirth

• checkout DXX-Rebirth from https://dxx-rebirth.svn.sourceforge.net/svnroot/dxx-rebirth
• change the SConstruct script to call sdl-config as ‘sh sdl-config ‘:

...
Flags and stuff for all platforms...
env.ParseConfig('sh sdl-config --cflags')
env.ParseConfig('sh sdl-config --libs')
env.Append(CPPFLAGS = ['-Wall', '-funsigned-char'])
...

• finally, in the MSYS shell, built with:

scons sdlmixer=1

Final Remarks

I had trouble with the latest version of PhysicsFS (1.1.1) because it uses cmake. For some reason it failing to find some prerequisites in MSYS. I also had trouble with version 1.0.1 of PhysicsFS (this is the version the official d1x-rebirth_v0.55.1-win.zip is built with) because the built failed with the following error:

warning: cannot find entry symbol _DllMainCRTStartup@12; defaulting to 00401000
...
undefined reference to WinMain@16

If you notice any problems or mistakes in this post, please mention them in the comments.