Posts Tagged ‘Python’

Composing renders in a strip

Tuesday, January 6th, 2009

First of all happy new year to everyone, then let’s talk about this post topic… :)

During these days I was relaxing and practicing subdivision modeling, after a long time away from Blender I was back to the dream of creating a convincing human head model, but my programming side win the day. :D
While I was studying in detail some face key parts topology from here, I noticed the PiP-like composed images attached to the first post…

Showing camera keyframes

Showing camera keyframes

The previous night I was thinking of a way to automates the process and today it becomes reality in the form of a Blender Python script: it is capable of producing an image which is composed of multiple rendered frames, think of a daily comic strip and you understand the name ;).

The user can select which frames to render specifying a string similar to the following one: “1-3, 5, 7, 9-11“.
Moreover it is possible, of course, to choose the size of a single frame and the composed image table dimensions, i.e. how many rows and columns it should have.
Have a look to how well my topology study renders fit the script purpose. ;)

The resulting composed image

The resulting composed image

This second script is a bit more complex than my first one, making use of the Registry module to load and save options and the Draw.PupBlock() method to display a bigger GUI.

Of course it is released under the GNU GPL License and available online, download it from here.

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Posted in 3d Graphics, Programming | No Comments »

Automatic parallax map generation with Blender

Saturday, October 18th, 2008

It has been a long time since I last wrote something here, during these months two new things happened that are worth to be mentioned: first of all I’m really close to graduation!
Well, actually I need to pass the last exam and spend a period of at least four months of internship, nothing is sure now but I’m in close contact with a game developing company… ;)

The second thing is closely related to this post instead, a couple of months ago I began to convert, following M3xican’s advice, my OpenGL demos to object oriented C++.
What I have now is really not much, nevertheless my class library can load a Stanford PLY model, it is ES 2.0 compliant (this means it will be easily converted to “Pure” OpenGL 3.x), and it can already display both parallax mapping and depth of field!

I’m not going to publish any screenshot by now because I think it’s not the time yet, what I’m showing you is a easy script, my first one, which I wrote yesterday night using the Blender Python API.
What it does is really simple yet time-saving, you select a high-poly and a low-poly model, run the script from the Object->Scripts menu and watch Blender baking your normal and height map and then saving them.

Blender parallax maps

I have also set up an easy compositing nodes configuration to mix the two images in a single parallax map with height data encoded in the alpha channel.

Blender parallax maps nodes

You can download the script from here.
Everything is very simple (and funny!) with the astonishing power of Blender! :)

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Posted in 3d Graphics, Programming | 1 Comment »

A slighty smarter setup.py for PySoy r64

Friday, June 1st, 2007

While working on PySoy I was really disappointed by the policy adopted by the setup.py script, anytime I launched it the result was a recompilation of *all* the sources, this was really annoying and slow.

Python transparent logo

What came after was just that I decided to hack it a bit and make it behave more like a standard build tool, that is to control the modification time of a source file in order to choose whether it is updated or need a fresh compilation.

The new policy for the script is very simple, but useful enough to save plenty of time.
It is aware of the following cases (thank you Arc for tips on how to deal with the last one):

  • a .c file is missing, pyrex should compile the .pyx file
  • a .pyx file is newer than the corresponding .c file, an update is needed
  • a .pxd file is newer than any .pyx file, a global recompile is needed

The last point is not optimal, of course, but it’s a lot simpler than specifying all the .pxd dependecies for any .pyx file, and, anyway, quite close to being optimal, because of the thick web of cross dependencies which actually exists in PySoy.

Here is the piece of code which performs the magic:


# Convert Pyrex sources to C if using Trunk
if version == 'Trunk' :
  import os
  from stat import *
  from Pyrex.Compiler import Main

  options = Main.CompilationOptions(defaults=Main.default_options, include_path=include_path)

  newestpxd = 0
  for dir in include_path:
    for pxdsource in os.listdir(dir):
      pxdsource_path = (os.path.join(dir, pxdsource))

      if os.path.isfile(pxdsource_path) and pxdsource.rsplit('.', 1)[1] == 'pxd':
        if os.stat(pxdsource_path)[ST_MTIME] > newestpxd:
          newestpxd = os.stat(pxdsource_path)[ST_MTIME]

  for pyxsource in pyrex_sources:
    compilation_needed = False

    if os.path.isfile(pyxsource.rsplit('.', 1)[0] + '.c'):
      ctime = os.stat(pyxsource.rsplit('.', 1)[0] + '.c')[ST_MTIME]
    else:
      ctime = 0

    if newestpxd > ctime:
      compilation_needed = True
    elif os.stat(pyxsource)[ST_MTIME] > ctime:
      compilation_needed = True

    if compilation_needed:
      Main.compile(pyxsource, options)

Well, actually Arc commited r65 too, simplifying the conditionals of the script even more, but this is another story. :)
Anyway, I hope to have made another little step into making the life of our team a bit simpler. ;)

Tags: ,
Posted in GameDev, PySoy | 2 Comments »

My Summer of Code begins with PySoy r44

Tuesday, May 29th, 2007

Summer of Code has started just today (even if currently it is only a “Spring of Code” :D ) but a little contribution of mine has already made his way inside the SVN repository of PySoy.

Code Obfuscation

But let’s start from the beginning…
After having shown to Arc an early draft of an UML class diagram for the current code I decided to come back to work on some test code I had written in the afternoon.
It was just a classical spinning cube demo to actually compare PyOpenGL versus Pyrex speed, I don’t report the results here because they are quite identical, if I haven’t done any mistake it should be the absolute minimum complexity of the code which actually determined this result.
Anyway, even without this proof I firmly believe in the power and speed of Pyrex. ;)

Going back to my commit, my changes affected a small yet important area of the code, I think we will remember it in the future. :)

BEFORE
In src/windows-glx/soy.windows.pyx:


gl.glClear(0x4100)

AFTER
In include/gl.pxd:


[...]
# Constants
  ctypedef enum:
    [...]
    # glPush/PopAttrib bits
    GL_DEPTH_BUFFER_BIT
    GL_COLOR_BUFFER_BIT
[...]

In src/windows-glx/soy.windows.pyx:


gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)

Was it better before or now? ;)

Tags: , ,
Posted in GameDev, PySoy | 4 Comments »

Python 2.5 support in globs r46

Wednesday, May 23rd, 2007

Yes, I should have written about it when I actually committed the revision, but I forgot completely. :D
About two months after Python 2.5 has been moved to the current repository of Arch I begun to think that maybe it was time to support the new release of our beloved language/interpreter.

Python transparent logo

I don’t know if it can be called “support”, but at least GL O.B.S. is now aware of it. :)
The changes are very simple yet of some importance.
First of all, pysqlite is not needed anymore if you have the integrated sqlite3 module:


if sys.version_info[:2] >= (2, 5):
  from sqlite3 import dbapi2 as sqlite
else:
  from pysqlite2 import dbapi2 as sqlite

Moreover I make use of the updated API of the webbrowser module:


if sys.version_info[:2] >= (2, 5):
  webbrowser.open_new_tab(Globs.BROWSE_URL)
else:
  webbrowser.Netscape('firefox').open(Globs.BROWSE_URL)

Another addition, not related with the support of Python 2.5, is the check_ver function, which checks if a particular version of OpenGL is available on the machine running GL O.B.S., this have opened the possibility to add an OpenGL 2 only test like GLSL_Parallax into benchmarks r47.

Python and GL O.B.S. are getting better and better. ;)

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Posted in G.L.O.B.S., Programming | No Comments »

Accepted for Summer of Code

Thursday, April 12th, 2007

“Dear Applicant,
Congratulations! This email is being sent to inform you that your
application was accepted to take part in the Summer of Code.”
Yeah, one of my two proposals has been accepted!

Dilbert Doodle

My first proposal was about working on GL O.B.S. under the Python Software Foundation, unfortunately it was very likely going to be discarded.
I learned this from a mentor who contacted me, he wrote that my application was based on a personal program and that it would have been hard to find someone to mentor me, moreover I wouldn’t have contributed to the Python community. He also added that I could have been a good candidate for his project, he is, indeed, Arc Riley, Project Manager of PySoy.
And so I did, I wrote another application and, this time, it has been accepted. :)

My work will be to integrate multi-texturing in the PySoy rendering loop and API, document API additions, test the whole under many different free software drivers and then implement some related techniques, like bump or normal mapping.

I’m really glad of this opportunity, I will learn many interesting OpenGL and Python topics and I will improve my design, teamwork and communication skills.
Thank you Google! ;)

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Posted in Rants | 4 Comments »