The system shows the result with four split windows as Figure 7.1. Different views collocate with the log window and the Figure 7.2 to speed up the Zometool construction.
The system transforms the polylines to the Zometool struts, and we provide the con-venient user interface for constructing the result. User can look up the struts informations for each node to speed up the process of building up the result.
Figure 7.1: Split windows for result construction. The biggest one shows the whole model, and three right windows show the selected point with different view direction.
They are front view, back view, view with the same direction as left window from top to bottom. Besides, there is a log window at bottom to show logs about the vertex informa-tion(the edge indices to use) when user click the vertex.
Figure 7.2: Aid for Zometool construction. It shows indices of all directions on the node.
The left node is the front view for the up right window, and the right node is the back view for the middle right window.
Figure 7.3: Screenshot of practical graphical user interface without log window.
Figure 7.4: Screenshot of practical graphical user interface with log window and black background.
Chapter 8 Experiment
For supporting the physical analysis system, we measure some physical parameters.
We measure the bending moment, shear force, and friction.
Bending moment is about the tolerance of bending, and the measuring method is show in figure 8.1. There are two methods to judge the safety as figure 8.4 and figure 8.5.
Shear force represents the force which tenons can bear, so we try to add force on the strut near the node and perpendicular to the direction of strut. Figure 8.2 shows it and figure 8.5 is the stopping condition.
Friction is the resistance force to stabilize the tenons and mortises, and the measuring method is show in figure 8.3.
Yellow/Triangle Blue/Rectangle Red/Pentagon
bending moment 9.4kg•cm 18.3kg•cm 13.9kg•cm
shear force 7kg 9kg 9kg
friction 1kg 1.5kg 2kg
Table 8.1: All data of measurement results
Figure 8.1: The method to measure bending moment. We tie the dumbbell to the middle of the strut, and ensure that the strut would not contact the chair.
Figure 8.2: The method to measure shear force. We tie the dumbbell to the strut near the node, and stop until the situation as figure 8.4 or as figure 8.5.
Figure 8.3: The method to measure friction. We tie the dumbbell to the node and hold the other side of the strut. We keep increasing the weight until the node dropping.
Figure 8.4: The extreme situation for three types of struts. The color of the middle part of struts become lighter, and we stop adding force when it happens. Weight of dumbbell for yellow strut is 3 kilogram; Weight of dumbbell for blue strut is 5 kilogram; Weight of dumbbell for red strut is 4 kilogram.
Figure 8.5: The tenons after undergoing the extreme situation, and it can be the judgement standards for the structural safety. If the color of tenons are lighter, it is the warning for safety.
Chapter 9 Conclusion
We have presented an system for large-scale rapid-prototyping that enables users to semi-automatically generate a Zometool structure with a 3D model input. The main prop-erty of the approach is non-manifold based structure to rapidly fit the features and de-crease the amount of building units in the same time. In contrast to the previous works about Zometool, we can use less building units to construct the model in the same size, because of our sparse structure, so we can also build up the result faster. And we provide a convenient GUI for user to speed up the process of construct the result. The proposed technique can be use as the large prototype in exhibition, the the props for stage play, and all situations which need the prototype constructed rapidly.
3D Printer TVCG GMOD Ours
Unlimited output size X O O O
Reusable X O O O
Feature preserving in low resolution - △ X O
Can output different size - △ △ O
Table 9.1: Table about difference between our system, 3D printer and previous works.
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