In this post i will explain how to use path constraint and snapshot tools to create continuous multiple objects. I am using this tools oftenly at work. For small scenes copy-paste could be easier to use but in huge scales snapshotting is much more time saver. I will post a few different renders below the explanation as example.
Before the start I created some kind of coal mine enter as you see above. Its only for the tutorial, I did not spend much time on it. Then I simply created a curved line starting from inside of the gate. It will be the path of our railroad.
Then I fit the line to the earth by playing with vertices. The earth plane has some ups and downs.
I created the wooden rail holder at the left side to put it below the rail.
Under the motion panel and assign controller drop down menu you will see position, rotation and scale. To assign a controller to transformer I selected position and pressed the assign controller button above the selection. After selecting path constraint from the list, it will be added to the object.
After adding path constraint, Path Parameters dropdown menu will show up. Under the menu Add Path button lets you choose which line will be followed by the selected object. I picked the path I created before. Usually the result is out of the rotation than how it must be look like. So I rotate it manually to find a position as I want. I recommend you to press follow button that I marked in the picture above before the manual rotation. Otherwise it will be unrotate again. Follow check lets rotate the object that controlled by path constraint on the way of picked line.
Now the object has a path animation. It can be seen by scrolling the timeline from begining to the end.
Snapshot can be reached under “Tools>Snapshot”. This tool can make a copy of the mesh within any single time or between a range in timeline. I have an animation of object that i want to copy in a range of time. So I checked Range and copied it 12 times as the lenght of my path.
The result is fine to me. I drew two lines more to create rails. And this is how it looks.
I also created the two pictures below. The one with city lamps is for this tutorial and the one with roller coaster is a product.