Blender
Blender (download) is a free and open source 3D modeling package that be used to create models for Source. Its only limitations are the absence of an exporter for the VTA files required for flex animation or a fully-functional SMD importer.
SMD exporters
The only plug-in that can export reference, collision and animation SMDs is Dvondrake's.
There is an SMD Importer by 3D2Toy, but it doesn't work too well.
Installation

Extract the .py script files of your chosen plug-in to:
- Vista
%userprofile%\AppData\Roaming\Blender Foundation\Blender\.blender\scripts\
C:\ProgramData\Blender Foundation\Blender\.blender\scripts\
- XP
%userprofile%\Application Data\Blender Foundation\Blender\.blender\scripts\
C:\Program Files\Blender Foundation\Blender\.blender\scripts\
- Linux
~/.blender/scripts
Under Windows, whether you install to %userprofile%
or Program Files
/ProgramData
depends on which you chose to use when installing Blender. The active folder will exist and be filled with existing .py files.
Learning Blender
Blender has a very unusual interface that takes some getting used to. Matters aren't helped by its preference of hotkeys over of visible buttons. Nevertheless, learning it is quite achievable:
- Official help portal
- Blender 3D: Noob to Pro (Wikibook)
- Blender Basics- 3rd Edition (printable classroom textbook released under Creative Commons BY NC SA)
Blender and Source
- Dvondrake's SMD export video tutorial covers creating and texturing a simple static object
- The Blender Modelling Walkthrough is a complete, step-by-step guide to creating exporting a static model with Dvondrake's plug-in.
- See Animation in Blender to learn how to rig and animate in a way that survives SMD export.
- Blender renders both sides of a polygon, but Source only renders the front. You can bring Blender into line by:
- Making sure the Buttons window is visible.
- Switching to the Editing panel (F9)
- Under Mesh, un-clicking the Double Sided button.
- If you find you need to flip any polys, either use Ctrl+n to make everything point outward, or select those that need to change and press w,0.
- Because Dvondrake's exporter only exports the currently-selected object, you can have reference and collision meshes in the same scene. Use layers to easily show/hide different elements of the model.