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A Guide to Modalys Objects

Objects - The Building Blocks of Modalys

An object is a simulated vibrating body which serves as the basic sound producing element in Modalys.

Objects are internally described using a set of modal data (a set of frequencies, loss coefficients and modeshape description for each frequency). They therefore have a linear response to excitation – this means that if a string behaves a certain way when plucked 10 cm, then it will do the same thing, exactly 100,000 times more, if you pluck it by 10 kilometers. Fortunately, Modalys objects are unbreakable, and need not be insured when taken on tour! (One can, however, obtain interesting nonlinear effects in Modalys using connections, which will be discussed later.) Objects are created in slightly different ways, depending on the interface being used (Lisp, OM, Max/MSP, etc...), but the basic Modalys command that is used (in a text-based environment) is “make-object” followed by the object type and a list of parameters.

(make-object object_type list_of_parameters)
As far as the user is concerned, an object can be considered to be the physical body which it represents, even though there a few essential differences to be taken into consideration:

  • Modalys objects are linear models. Thus, for example, a rectangular plate object cannot be broken no matter how hard it is struck.

  • Modalys objects only vibrate (or otherwise change position) in a limited number of predetermined axes (either one, two or three, depending on the object type).

  • Some Modalys objects have “ideal” parameters which cannot exist in reality. The membrane objects, for example, are just surfaces with tension, size and mass; their thickness is zero and their density is infinity.

  • The physical parameters of Modalys objects are only used to calculate their vibrations. Thus, two objects cannot collide or otherwise interact unless they are specifically told to do by the user via the use of a connection.

The remainder of this section is devoted to the types of objects that Modalys can create (given a list of physical parameters such as density, tension, etc...) Many objects share general parameters, but specific information about each object's parameters, accesses, etc... is provided on the documentation page for that object.

Objects interact with other Modalys items (such as controllers and connections) through accesses, described in detail in the next section. For now, it is enough to know that an access is a point on a Modalys object that allows it to communicate with other Modalys objects, and that different objects have different access types, depending on how the objects vibrate. For example, a bi-string object can be accessed in the 'trans0 (horizontal) and 'trans1 (vertical) directions, while an air column must be accessed in the 'long (meaning longitudinal - across the length of the tube) direction. The available access types for each object are also described in the following object description pages.

We have subdivided this section into the following categories:

We suggest you first read the section on object properties in order to better understand some of the object options presented in the subsequent reference section.