Multiframe adopts the convention that joint 1 is always the joint to the left of the member in the front view and in the case of members which are vertical joint 1 is at the bottom, joint 2 at the top.
 
In the case of a member which lies in the xy plane, joint 1 will be the joint on the left and joint 2 will be the joint on the right. In the case of a member which lies in the xz plane, joint 1 will be the joint on the left as viewed in the right hand view and joint 2 will be the joint on the right as viewed in the right hand view.

The modal shapes created after analysis are non-dimensional and merely reflect the shape the structure would have when vibrating at a given natural frequency. Currently dimensions are shown but the shape is actually scalable to any size. We don't show the induced stresses or actions that result from dynamic analysis as these are not meaningful.

For any continuous structure there are theoretically infinite natural frequencies, but generally engineers dealing with real structures only need to consider those natural frequencies that are likely to occur in the real world. These are usually the lowest natural frequencies for the structure. Multiframe4D calculates from the lowest natural frequency upwards to a possible of 20 natural frequencies.
 
To carry out a modal analysis using computational methods we approximate the continuous system by discretising the structure into a finite number of degrees of freedom. Each degree of freedom allows us to calculate one natural frequency. The more degrees of freedom the more accurate the solution.
 
A good rule of thumb is that the minimum number of degrees of freedom should be at least double the required natural frequencies. Multiframe enforces this rule.
 
Each node has 6 degrees of freedom. A structure with 2 nodes, one fixed, would eliminate the degrees of freedom for that node, so you are left with 6 degrees of freedom in total. Thus considering the rule above, Multiframe4D will only return a maximum of 3 natural frequencies.
 
The solution is to use the subdivide command to increase the number of nodes in the structure and therefore the degrees of freedom. If you experiment with different levels of discretisation you will notice improvements in the accuracy of the solution for the higher natural frequencies as the number of nodes is increased.

When you have generated a dome, you will find that the reason the orientation of the members is not exactly what you expect is because of the convention that Multiframe uses for determining which is joint 1 and which is joint 2 on a member.
 
The orientation depends on this ordering since the orientation is defined relative to a vertical plane passing through the two joints and looking in the direction from joint 2 towards joint 1. Multiframe adopts the convention that joint 1 is always the joint to the left of the member in the front view and in the case of members which are vertical joint 1 is at the bottom, joint 2 at the top.
 
In the case of a member which lies in the xy plane, joint 1 will be the joint on the left and joint 2 will be the joint on the right. In the case of a member which lies in the xz plane, joint 1 will be the joint on the left as viewed in the right hand view and joint 2 will be the joint on the right as viewed in the right hand view.
 
For other members which are at arbitrary orientation, the joint numbering will stay the same as that when the joints were generated. It is important to consider the order of the joints in the member when viewing it's orientation. If you are viewing the table of members in the Data Window you will need to check the numbers of joint 1 and joint 2 in the left columns when reviewing the member orientation. The graphical displays in the windows should be correct if you take this into account.

The default behavior of Multiframe in regards to pinned and fixed joints and members is that all members and all joints are initially fully rigid. This means that there is complete moment transfer across each joint. If you make a joint pinned, then this releases the moments and torsion at the ends of all the members attached to that joint. It also sets the rotations of that joint to zero.
 
If however you release the moments at the end of a member using the Member Type command, then in the Member Type dialogue you have an option of which moments and torsion to release.
 
In general you will want to use a pinned joint when analyzing a truss structure and you will want to use the pins at the end of a member when you want to have a rigid frame where a part of the frame is pinned.
 
You should not pin a joint and also pin the end of a member attached to that joint.
 
Also keep in mind that releasing moments on a member releases the local rotations and moments whereas applying a pinned joint restraint releases the global rotations and moments.