Q1: Does the Railclone Pro build up the mesh every time when it load the scene ?
If I have a scene with heavy use of Railclone Pro object, will this build-up process slow down the loading speed of my huge scene ?
Not exactly. In the scene file, RailClone only stores the information to build the object, and the segments.
If segment is 'embedded', RC keeps a copy of its mesh internally. If not, it's taken from the scene.
When scene is loaded, always RC rebuilds the object. But not the full mesh, just the bounding boxes and the minimal data required for the viewport.
On render, it computes the instances, and builds the geometry which cannot be instanced.
Q2: Is it possible to cache data that have been built-up to harddisk ?
This is not necessary, as explained above.
Q3: Will it be faster process or smaller files size that use emblemed segments objects(delete the segments used by Railclone objects in the scene) instead of real objects in the scene ?
There is not difference. Obviously it's necessary to keep a copy of the segment (embedded or in the scene), but performance is identical.
If I delete all the segment objects of Railclone pro objects, will the object userproperties and modifiers and some custom tracks be kept in the segments of Railclone objects ?
That depends, because some data it stored in the object (as modifiers), and other in the node (as user properties).
First of all, i suggest you read this link
to understand the difference between 'object' and 'node'.
When you delete a segment from the scene, RC keeps internally a copy of the object (but not the node).
Although the data stored in the node is lost, that is not a problem because really is not used by RailClone. For example, user properties (stored in the node).
How can I share segments between Railclone objects ? This is very important.
RailClone always tries to share the segments between different RCs. The easiest way for you is to use segments from the scene.
For 'embedded' segments, it's most difficult to know if are shared or not. RC uses several rules to share them as most of possible, for example when a same library style is assigned to several RCs, or when a RC object is cloned.
Segments are stored in the 'sobjref' parameter (an array). You would compare this parameter from Maxscript, to know if segments are shared or not, but i discourage this practice. Use scene segments instead.