2.5. In the Path Parameters rollout, click Add Path and click the spline in a viewport. Now the camera follows the length of the path during the whole length of the animation, but we want it to have a distance to the camera target, so go to the final frame, activate Auto Key, set the Default Tangent to linear, and type in 90% in the %Along Path field.
2.6. Create a dummy, and add a Path Constraint to make it follow the same spline, but now (with Auto Key on) go to frame 0 and type in 10% in the %Along Path field. Turn off Auto Key.
2.7. Align the camera target to the dummy, and then link the camera target to the dummy. Play the animation, and double check that you now have a nice animation of a camera following the camera target at a constant distance.
2.8. Why use the dummy and not apply the Path Constraint directly to the camera target? Remember that jittering we were talking about? Select the camera target, and assign the Noise Position controller to it, instead of the Path Constraint. In the Noise Controller dialog, de-select Fractal Noise, enter 0,2 as Frequency, and 2,0 as X, Y and Z Strength. This gives a nice turbulent bounce to the camera.
2.9. Create a cylinder with Radius 45, Height 440, Height Segments 40, Sides 15, and align it to the path (position and rotation) using the Align tool. Right-click the cylinder, go to Properties and de-select Renderable. Also, make sure the cylinder's Backface Cull is turned off.
2.10. In the Modify panel, open the Modifier rollout, and select PathDeform (WSM). It's very imortant that you choose the World-Space Modifier version (WSM), and not just the normal PathDeform. Select the path.
2.11. Now you can see the cylinder stretching along the path. If your path coordinates deviated radically from the ones I described earlier, you will need to adjust your cylinder's Length, Radius etc. Play the animation in the camera viewport, and it should look something like a tunnel effect from an Amiga demo, but without the plasma!
2.12. For an extra touch, add a banking effect to the camera: set Default Tangents to auto, activate Auto Key, select the camera, and press F12. Go to frame 25, and set Roll to -25. Go to frame 75 and set Roll to 25. Go to frame 100 and set Roll to 0.
2.13. If you want, now is the time to merge your favourite aircraft model into the scene, and add the same Path Constraint once more. Again, go to frame 0 and set the "%Along Path” to 10. Activate Follow and Bank, set the Bank Amount to 2, and the Smoothness to 1.
2.14. Also, load in a standard environment map, for instance, CHROMBLU.JPG from the Max library (not that we'll be seing a lot of background, but it's better than black)
3.1. Collapse the tunnel (Cylinder01), add a TurboSmooth modifier, and set Iterations to 2. Then add a Noise modifier on top. Set the Noise Scale to 40, activate Fractal, set Iterations to 2, and set X, Y and Z Strength to 40.
3.2. Add a Push modifier and set it to -10 to make the walls bulge out in round shapes (if you think the polys are moving in the wrong direction when you use the Push modifier, keep in mind that we are watching the inside of a cylinder, and all the polys are backfacing).
The cylinder is now a representation of where the clouds will be.
3.3. Press "6” to open the Particle View. Change the Amount to 2000, and select Cylinder01 in Position Object. Your tunnel should now be populated with billboard particles. Make a test render of that, to see how you're doing.
Not bad, but we're still using traditional lighting, based on polygon angles - that's the only reason for the grey shades you can see in the render. This isn't a liable solution, because when the billboards turn to follow the camera, their angle relative to the light source will change, and so will their brightness.
3.4. But before we begin lighting the cloud tunnel, let's work on the color. We can't apply any polygon-mapped texture, but we can make large chunks of color variation. In the cloud material, click the Diffuse Color slot, and select Noise from the Map Browser..
3.5. Choose Fractal, High=0,8 Low=0,2 Levels=10 and Size=100. Instead of black, use 60, 90, 115. Turn the cloud material's Self-illumination up to 100, and render.
What we have created is a large world-space texture variation. The reason we can't use polygon-mapped bitmap textures with billboard particles is that when they turn to follow the camera, they will intersect in and out of each other, and the textures will "pop” in and out. But with a world-space texture, two intersecting polygons are guaranteed to have the exact same color information at the intersection point, so the intersection is invisible.
(Technically, world-space textures aren't perfect either, because when the billboards turn, their surface will move through the world-space texture information, and the texture will appear to "crawl” over the surface. But with a pattern this large, it's not a problem).
3.6. In the top viewport, create a Target Direct light that lights the cloud tunnel from the side