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## Constraints and their Effects

Generally it is the rule that SISCAD-P maintains the constraints that once have been saved for geometrical objects.
If the position of objects to each other is not exactly determined with constraints, you may modify this position with manipulations as for example MOVE or ROTATE. The strategy of the manipulation is to change as less as possible within the entire construction.
If objects, for which constraints are saved, are copied with the command COPY, the copies do not automatically have these constraints. If you want to know this, you only have to activate the auto constraint mode or work with constructional relations.
The TRIM command is more difficult. When trimming one object it sometimes is the case that two objects appear and the old object disappears. Constraints are not automatically transferred to the newly created objects.
Objects that have the constraint FIXING, may be manipulated directly in
SISCAD-P. The reason is that with a direct manipulation SISCAD-P assumes that you untie the fixation at the old position and determine the fixation for the new position.
Constraints and Assemblies
Constraints between geometrical objects which belong to different parts are not permitted. Despite this, you have the possibility to create relations between these parts.
Each part has a so-called positioning point, i.e. its origin of co-ordinates. This positioning point will be positioned onto an existent point (reference point) when positioning it into a module. Now it is possible to tie these reference points of the individual parts together so that the manipulation of the individual parts is subject to certain guidelines.
It is self-evident that these points can also be dimensioned. In addition, it is possible to tie parametric dimensions, which belong to different parts, together with the help of formulae.