By Dennis Collin
Recently on Cadline Community
I described an easy way to get cameras to follow paths with a aim to produce walkthrough animations. The problem is it used a script which only works for standard cameras used by Mental Ray or the Default Scanline Renderer.
However if using other renderers like Vray then the script won't work with the special Vray Cameras. Or if you wish to get OBJECTS to follow cameras, like crates or parts in a factory model then another method is required. Keyframing is obviously one approach but often with a Visual Design Model, lines like 'AutoCAD Polylines' might be available, showing route of travel or similar and these objects coud be employed to create our animation replicating a component following an assembly line.
Although not quite as straight forward a task as the Walkthrough Assistant it nevertheless provides a serious tool to produce quite effective animations.
Supplementary tools like 'Track View' can enable users to get elements to slow down or stop with the odd Key Frame tweak used if you want an element to turn a specific way. Or to wait for a certain event to happen (like a door opening or light to come on)
In this simple scene I am going to get a simple chamfered box to follow a path. The path needs to be fairly clean, with no kinks or excessively sharp corners which would make the travel 'jerky'.
It is also worth setting the frame count to a suitable number to at least 400 frames. This will ensure playback is clearly visible and doesn’t play too fast, which means you cannot see clearly what’s going on.
Select the Box, and choose the 'Motion' tab - 4th tab from the Left
We then can assign a path constraint to the said object (which could theoretically be a camera or camera target)
Picking the path (Line001) will then move the Box to the beginning of the line. (Pressing the playback button should show the box travelling along the path)
This basic animation can be tweaked by using tools like '% Along Path' which will allow you to 'move elements further along the path' to form a train kind of object. Or a Camera Target object if doing a Walkthrough animation. By Ticking the 'follow option' will get the element to turn around corners and Bank will make the elements bank into a corner like a fast travelling motorcycle.
I had to tone down the banking amont to about 0.1 to get a reasonable behaviour.
To replicate a conveyor or perhaps a fairground ride one can duplicate the object path then and perform a sweep modifier to give a surface for the boxes to ride on!
(Shown in video window)
To have large number of elements like gravel or rubble on a conveyor I will use a similar technique using max particles in the near future, in another blog post.