Its been a busy few weeks building, and rebuilding, the chassis and getting the animation to work. I'd like to think I know a little more about animation in Blender but there is still much to learn.
However, the Walschaerts valve gear animation works - at least for the bits you can see in the loco. After studying various Walschaerts animations on the web I tried to create a cutaway version showing the main piston head and valve heads. After having a few guesses as to the shape of the valve heads, their position and the location of the steam ports I couldn't get it to work so that the steam seems to go in the right direction. Big Bertha's valve configuration is a bit different from the more common variety so perhaps there is something else I don't know.
A couple of days back, Brian (Kennilworth) provided a really interesting photo from a BackTrack article that shows some of the configuration of the two internal pistons and the crossover vents. I could include that in the model but it would never be seen so it would be poly waster. A shame really.
Here are two pics of the left side of the loco as it appears in Trainz as a scenery object. I have a couple of minor changes to make as a result of Brian's photo and then I will texture the meshes. Once that is done I can mirror the mesh and the animation to the right hand side.
The chassis and valve gear have a very simple material that makes individual components difficult to see in these shots. The purpose of exporting the chassis as a scenery asset was to check out the animation. The wheels simply rotate once per second.
The piston housing cover has a distortion due to a hole in the cover (deliberate) and application of the smooth operator to the mesh. If I cannot get rid of the distortion I will remove the hole and include it in the texture.
This how it looks in Blender with the mesh in "solid" mode. It's impossible to see anything clearly in wireframe mode.
And finally a Blender view of the animation bits including armatures, bones and lattices. This is the side on view.
The next episode should (hopefully) include the textured and full chassis.
Paul
However, the Walschaerts valve gear animation works - at least for the bits you can see in the loco. After studying various Walschaerts animations on the web I tried to create a cutaway version showing the main piston head and valve heads. After having a few guesses as to the shape of the valve heads, their position and the location of the steam ports I couldn't get it to work so that the steam seems to go in the right direction. Big Bertha's valve configuration is a bit different from the more common variety so perhaps there is something else I don't know.
A couple of days back, Brian (Kennilworth) provided a really interesting photo from a BackTrack article that shows some of the configuration of the two internal pistons and the crossover vents. I could include that in the model but it would never be seen so it would be poly waster. A shame really.
Here are two pics of the left side of the loco as it appears in Trainz as a scenery object. I have a couple of minor changes to make as a result of Brian's photo and then I will texture the meshes. Once that is done I can mirror the mesh and the animation to the right hand side.
The chassis and valve gear have a very simple material that makes individual components difficult to see in these shots. The purpose of exporting the chassis as a scenery asset was to check out the animation. The wheels simply rotate once per second.
The piston housing cover has a distortion due to a hole in the cover (deliberate) and application of the smooth operator to the mesh. If I cannot get rid of the distortion I will remove the hole and include it in the texture.
This how it looks in Blender with the mesh in "solid" mode. It's impossible to see anything clearly in wireframe mode.
And finally a Blender view of the animation bits including armatures, bones and lattices. This is the side on view.
The next episode should (hopefully) include the textured and full chassis.
Paul
