Fugen's fundamentals or common rules are explained

## １. Command's rules or common processes

Commands follow the rules below:

(1) command cancel ESC key

To cancel a command halfway(terminate withoud any process), press ESC key. All commands terminate without generating or updating models. The models state returns back to before commands are invoked.

(2) End of multiple points or objects to select Return key

When number of input points is uncertain as NURBS or polylines, press return key to tell fugen the end of input. And when number of objects to select is unknown, the same. For example, Transform commands take as many objects as operators select for the targets. The number is uncertain. In thes cases, tell fugen the end of input by pressing return key.

(3) Position input Cancel BackSpace key

When multiple points are input, sometime cancellation of the previous input is necessary. In this situation, Backspace key typing does it. Backspace key is accepted when some position input(we call it locate) is required.

(4) Command Normal termination Return key

Alothough many commands terminate when some definite number of points are input, some commands end with definite termination designation. In these cases return key is used.

For example, polyline command accepts indefinite number of points. Polyline command recognize the end of position input when it accept return key.

(5) Command's option Key typing

When a command requires some input, it shows a message in a message pane of the Status Bar. This message sometimes includes a letter enclosed by quotes []. This indicates the command has some options that are invoked by typing the letter. The following example indicates Parameter line extraction: Select isocurve kind[D-direction(U curve)] [P-parameter value input]

1) Pressing the key D changes the parameter direction

2) The key P shows a dialogue to input parameter value from KB.

(6) Consecutive same command execution. Return key

When fugen system is idling, typing return key invokes the previous command executed. Fugen remembers previous command, and executes it.

(7) Interrupting command

While a command is executing(e.g. on the way to input points) some other command can be invoked. For example most analysis commands can be interruptly executed.

The interrupted commands continue after the interprupting commands terminate.

## ２. Pick Operation(Object Selection)

### Pick operation 1 - Single Pick

Focus the cursor over a target picture and push the left button to selct a single one. When multiple pictures are detected inside the cursor area, the following dialogue is displayed to designate which one of the objects is to pick. The dialogue below prompts to select one of the highlighted LBRep(B-Spline curve) or the black straight line. Both curves are inside the cursor scope and one of them is necessary to select. Select the curve kind in the dialogue by the cursor or arrow KB keys. The selected object is highlighted in color yellow.

### Pick operation 2 - Multiple Pick

(1) Rectangle Area selection 1. With the left mouse button down, move the cursor from left-upper to right-bottom position to select all the pictures whose whole parts are inside the rectangle. In this case, the rectangle is displayed in solid lines.

(2) Rectangle Area selction 2. With the left mouse button down, move the cursor from right-bottom to left-upper position to select all the pictures whose fragments are inside the rectangle. In this case, the rectangle is displayed in dashed lines.

### Pick Operation 3 - Additional Selection

To the already selected pictures, additional selection is possible by the pick operation with the control or shift key down. The both keys have the same effect. (1) Pick unselected objects with ctrl, or shift key. The selcted ones are added to the selected objects. (2) Pick selected objects with ctrl, or shift key. The selected ones are turned into unselected ones.

### Pick Operation 4 - Command's special pick

Some commands enable special pick operations. Refer to the each command help about the detail. The special pick operations are: (1) The above rectangle pick operations may be prohibitted. Only single pick is possible. (2) The change of selected and unselected is prohibitted. (3) Picture kind of selection is limitted(to curves only, to surfaces only, etc). (4) Only the boundaries selection is allowed.

# 3. Positional Data Input(Locate)

Positionla data(3D space coordinates) is input through (1) cursor, or (2) KB. We call this coordinates value input as Locate. When multiple points are input, the following common input process is provided: (1) Input data termination: Inputting Enter key from the KB means the end of the input. (2) Cancel of the last point data input: KB Backspace key means cancel of only the last input point. (3) Cancel of the whole input data: Escape key cancel the current command and cancel the whole input data.

## 3.1 Locate by Cursor

When the command requests point data input(e.g., point coordinate data input to make a picture), the cursor is changed into the special point data input cursor(the cross cursor of the top left window below) to indicate the locate operation is requested. The snapshot of the screen below is the one of locate operation to input a through point to make a spline curve. The window is divided into 4 views, which are top, left , right, and perspective one. The same position in 3D space is projected onto the 4 divided views.

The center small rectangle cursor of the corss is position data "fugen" detected. The snap function that is explained later restricts the input position onto somewhat different place from the current cursor position. In the screen shot above, the mouse cursor is placed in (X,Y) view. The same point data is projected onto the other 3 views. The coordinate values "fugen" detected are displayed in Coordinate Value Display Area below the views. The values are of the position data of the cursor that is projected onto the CPlane(Construction Plane).

## 3.2 Locate by KB(by the function key F8)

When the locate operation is requested, that is, the cursor is displayed as the cross cursor, press F8 key to input positional data from the KB. When the F8 is pressed the following dialogue box is displayed.

(1) Previous Point:The last positional data input is displayed. When the input is the 1st one, nothing is displayed here.

(2) World Absolute Coordinate/World Relative Coordinate:To input world coordinate system values, mark one of these marks. Input the x,y,z coordinates by comma separated values in the edit box of the input dialogue like 1,2,3. To input the relative values from the previous input position, mark world relative coordinates. In this relative mode, the input values are added to the previous data.

(3) CPlane Absolute Coordinates/CPlane Relative Coordinate: are similar to abolute world coorndinate system. The difference is that CPlane's coordinate values are the ones of CPlane's. CPlane's Relative Coordinates are similar to relative world coordinate system. The difference is that CPlane's coordinate values are the ones of CPlane's.

(4) CPlane's Polar Coordinates(degree) are the ones on a CPlane. The polar coordinate system (l,theta) on the CPlane can be transfered to normal coordinates Q as:

Q=P+l*cos(theta)*uderiv+l*sin(theta)*vderiv..

Here, P is the origin of the CPlane, uderiv is the u-direction unit vector, and vderiv is the v-direction unit vector.

## 3.3 Snap function at Locate process

When "locate" is requested, Operator can set some restriction to the input data, called "snap restrictions". The snapped points are employed when the restrictions are met. These points are called object snap. Currently the following object snap functions are provided:

(1) Lattice(Grid) Point: Snapped to lattice points of the current CPlane. Although what spap kind is applied is displayed at the cursor in the other snaps, no information is shown only at the lattice point snap.

(2) End Point: Start or terminate point of a curve. "END" is displayed at the cursor.

(3) Neighbor Point: Neighbor point on a object. "NEAR" is displayed.

Lattice Point | End Point | Neighbor Point

(4) Center Point: A Center of an object. "CENTER" is displayed.

Center:Case of Curves
Center: Case of face

(5) Knot: NURBS has so called knot points. Knot snaps to the knot points. "KNOT" is displayed.

Case of Knot

(6) Face Vertex: Boundaries of Face consist of edges. The boundary of edge is called vertex, which is a connecting point of edges. Though surface does not have edges, we call the four corner points as vetex, instead.

Face Vertex

## 3.4 Locates by AETMode(Angle, Elevation, Tab)

Specially restricted input function by Angle, Ctrl key(Elevation mode), or Tab key is provided.

(1) Angle mode

Angle mode is a cursor restriction that limits the cursor movement on a straight line which makes a multiple of a specified angle against th horizontal line of the current CPlane. The limit is applied from the second input point.

How to Specify Angle mode

"Tool -> Object Snap -> Dialogue" opens a input dialogue of snap attribs. Angle value of the snap is specified from this dialogue.

The picture below is an example. In this case, 30 degrees is specified to limit the cursor on the straight lines that makes a multiple degrees of 30 against the horizontal line. Actually the yellow lines are not depicted. The origin of yellow lines of the picture is the last input point.

The angel value input from the dialogue is registered even if the mode is off, and applied when on.

Input points in angle mode are not always on CPlane.

When the previous input point is on the CPlane, the next point is on it. When the previous point is not on the CPlane, the point to input is so moved that the two poins are on the same plane that is paralle to the CPlane and make the angle on the parallel plane.

In addition to input from the attribute dialoge, the mode is turned On/Off from the Angle pane of the status bar. Pushing the left mouse button toggles On/Off of the Angle mode.

Angle pane of Status bar

When Angle restriction is enabled, the letters of ANGLE is displayed in blue color, and when disabled, displayed in gray. The letters of the Angle pane change according to the modes. When the mode is Tab, they are "TAB", and when Elevation, "ELEVATION". If the mode is active and displayed in blue, operator is able to disable the mode by picking the pane. Some commands use Tab, Elevation, or Planar mode internally to prohibit operator's mode update. These cases are indicated by showing the letters in red.

The above picture shows the example. This command inputs the scaling factor by the two white lines length ratio using TAB mode internally. The cursor movement is restricted only along the white straight line. The mode is not updated even if the pane is pushed.

(2) ELEVATION mode(Normal points against the CPlane by Ctrl key)

The special input mode of Ctrl key enables to snap points on the virtual normal straight line from a point on the CPlane. Typing Ctrl key, input a point on the CPlane by mouse left button. Fugen recognizes an infinite normal straight line that passes through the point, and since then, snaps the input points onto the nearest points on the line. "ELEVATE" is displayed in the Angle pane of the status bar in blue color. To disable the "ELEVATE" mode, two ways are provided:

1) Mouse-input of any point with Ctrl key down

2) Click Angle pane(ELEVATION in blue is displayed)

Points with Ctrl key down are not recognized as point input, recognized as Elevation mode update.

In elevation mode, points input in the view of elevation mode initiation are projected on the CPlane. This means the vertical points cannot input in the view. We need to input vrtical points in other views than the initial view, showing 4 views.

The above picture is the elevation mode input example. Though (x,y,z) view is the one in which the Elevation mode is initiated, (x,z) view is used to input vertical points onto the normal line.

Since the elevation mode is started in a (locate) command, termination of the command disables the mode to update to normal mode.

(3) Tab mode(Point input on Virtual line)

The special input mode of Tab key is applied to from the second input point. Let Ps be the previous point. Move the mouse point to a desired position Pe that makes a straight line from Ps to snap input point onto. Then type Tab key, without pressing mouse left button. Normally Pe is a point on CPlane, this may not be the case. Pe can be any possible point to input , e.g. some snap points. Fugen recognizes an infinite line from Ps to Pe, and since then, snaps all the points onto the line. "TAB" in blue is displayed in the Angle pane. The mode is disabled with another tabe key typing, or left button pushing in the angle pane of the status bar.

Points of Tab key typing are not recognized as point input, recognized as Tab mode update only.

Since the tab mode is started in a (locate) command, termination of the command disables the mode to update to normal mode.

"TAB" letters shown in the status bar

## 3.5 Locates by PLANAR mode

Planar mode restricts a point to lie on a same plane. When a planar mode is turned on, "PLANAR" letters on the status bar is displayed in blue color. To turn on, push left button of mouse in the planar pane of the status bar. In planar mode, the first point is located anywhere, the second or later points are restricted to lie on the same plane with the first point. The plane is the one that is parallel to the CPlane of the first point input, and that passes through the first point. When the view to input is changed, the CPlane at the new view is applied to parallel plane.

In the above example picture, the 1st point is input in upper-right main view, and the new point is going to input in the lower-right (x,z) view after the Planar mode is on. The CPlane in the lower-right view is the plane of Y=300, the Y value of the cursor point stays Y=0 of the previous point (0,0,0).

Planar mode is partially exclusive to AET mode. Although Angle mode is turned on together with Planar mode, Elevate or Tab mode cannot be turned on when Planar is on. If Planar mode is turned on while Elevate or Tab mode is on, Elevate or Tab mode is turned off. On the contrary, If Elevate or Tab mode is turned on while Planar is on, Planar is turned off.

## 3.6 Distance restriction mode

"Object Snap -> Snap Attrib Dialogue -> Distance Restriction" restricts the cursor within the specified distane away from the previous point.

Check the Distance Restriction and input e.g. 50 in the edit box to push the OK button, the muose cursor movement is limitted within the distance of 50 away from the previous point. When the mouse is moved at the poisition away from the previous point more than 50, the point of 50 distance is input.

## 3.7 Priority of the snap process

The snap processes are applied according to the following order: The previously processed position data is updated moreover at the next ones.

(1) Lattice Snap

(2) Object Snap(Neighbor, End, Center, or Face Vertex)

(3)Angle /Elevation/Tab Mode/Planar

Angle, Elevation, Tab modes are mutually exclusive. Elevation, Tab, and Planar modes are also exclusize.

(4) Distance Restriction

This is applied simultaneously with Angle/Elevation/Tab Mode/Planar