Introduction

JPatch is a spline-based modeling tool written in Java. It allows you to build complex, organic shapes using bezier-curves.

Modeling Rules

Objects in JPatch are constructed of 3D patches that represent curved surfaces. These patches are built up by drawing their outlines as a "spiderweb" of curves. This "web" is turned into patches according the following rule:

When you create 3 or 4 points that are connected in a loop, the loop defines the outline of a patch - with one exception: If all the points lie on the same curve, no patch is created.

Figure 1 shows the two possible 3-point-patches (3 points on 3 curves and 3 points on 2 curves) and the three possible 4-point-patches (4 points on 4 curves, 4 points on 3 curves and 4 point on 2 curves). The two loops on the bottom are not patches because all points lie on the same curve (left two) or are made of more than 4 points.

Figure 1 - Possible patches

The Main Menu

File
NewDeletes everything.
OpenJPatch has no own file format yet. Use Import > sPatch.
SaveJPatch has no own file format yet. Use Export > sPatch.
Save asJPatch has no own file format yet.
Import > Animation MasterNet yet implemented.
Import > sPatchImports a model in sPatch format. The new model will be appended to the existing one!
Export > sPatchSaves the model in sPatch format.
Export > POV-RayExports as .pov file for rendering with POV-Ray
Export > RenderMANExports as .rib file for rendering with a RenderMAN renderer.
ExitExits the program.

Look&Feel
MetalSwitches to the Java Look and Feel.
CDE/MotifSwitches to the CDE/Motif Look and Feel.
WindowsSwitches to the Windows Look and Feel.

Script
Shapes > CircleCreates a circle. You'll be asked for radius, number of segments and plane.
Shapes > GridCreates a grid. You'll be asked for grid size and dimension and plane.
Shapes > SphereCreates a sphere. You'll be asked for radius and number of segments.

Render
Java 3DStarts the Java 3D shaded preview (Java3D must be installed!). You will be asked for the number of subdivisions (4 is the default, use more for simple models and less for complex models). In the preview window you can rotate (dragging the mouse with left mousebutton pressed) and zoom in/out (dragging with right mousebutton pressed).

Info
AboutShows version and copyright information
CreditsShows the JPatch Team members

The Main Toolbar

NewDeletes Everything.
OpenImports a model in sPatch format.
SaveSaves the model in sPatch format.
UndoUndoes the last change on the model. Currently 20 levels of undo are supported.
RedoRedoes the last "undo" if no other change has been made.
Single viewSwitches to single view mode.
Split view horizontallySwitches to horizontal double view mode.
Split view verticallySwitches to vertical view mode.
Quad viewSwitches to quad view mode.
Move viewDrag with left mousebutton in a view to move the camera.
Zoom viewDrag with left mousebutton in a view to zoom in and out.
Rotate viewDrag with left mousebutton in a view to rotate the view.
Lock/Unlock XLocks/unlocks points on their X-axis position.
Lock/Unlock YLocks/unlocks points on their Y-axis position.
Lock/Unlock ZLocks/unlocks points on their Z-axis position.
Mesh modeSwitches to Mesh mode.
Muscle modeNot yet implemented.
Bone modeNot yet implemented.

The Edit Toolbar (Mesh mode)

Select/Move PointsESC
  • If you left-click on an unselected (red) control-point all previously selected (green) control-points become unselected and while you keep the left mousebutton pressed you can move the control-point.
  • If you left-click on a selected (green) control-point you can move all selected control-points by dragging with left mousebutton pressed.
  • If you left-click in the void you can draw a selector-rectangle by dragging with left mousebutton pressed. All visible control-points inside the selector-rectangle will be selected (or change their selection-state when SHIFT is pressed).
  • If you left-click while holding down the SHIFT key you can select/unselect this point while keeping other points selected.
  • If you move a control-point close to another one pressing the right mousebutton will weld the controlpoints.
    • Magnet Move ToolNot yet implemented.
    Add Curve SegmentA
  • If you left-click on a control-point dragging with left mousebutton pressed will attach a new curve-segment to the selected control-point.
  • If you left-click in the void dragging with left mousebutton pressed will add a new curve.
  • If you move the new control-point (without releasing the mousebutton) close to another one pressing the right mousebutton will weld the controlpoints.
  • When you release the mousebutton JPatch will switch back to the default (Select/Move) mode.
    • Add Multiple Curve SegmentsA Does the same as Add Curve Segment but doesn't switch back to default mode after you release the mousebutton.
    Scale ToolS
  • Dragging with left mousebutton pressed will scale the selection. The 3D-Cursor (the orange crosshair) acts as the pivot point.
  • You can set the 3D Cursor by pressing the middle mousebutton.
  • Holding down the SHIFT key restricts the scale-factor to integers.
  • You can scale even to the negative - which results in a mirror operation.
    • Rotate ToolR
  • Dragging with left mousebutton pressed will rotate the selection. The 3D-Cursor (the orange crosshair) acts as the pivot point.
  • You can set the 3D Cursor by pressing the middle mousebutton.
  • Holding down the SHIFT key restricts the angle to 45 degree steps.
  • Holding down the CONTROL key restricts the angle to 15 degree steps.
    • Tangent Tool/Select CurveT
  • Click on a control-point to show it's tangent and it's curvature value. Drag without releasing the mousebutton to change the curvature.
  • By clicking on the same control-point again you can select a curve segment (highlighted in yellow).
    • Delete Selected PointsDEL Deletes all selected control-points. Note that the control-points are just removed from the curves (the curves stay connected). If you want to open a closed curve or to split a curve use the Delete Curve Segment button.
    Detach Selected Points Detaches welded control-points.
    Insert Point When a curve segment is selected (with the Tangelt Tool/Select Curve), Insert Point inserts a new control-point.
    Delete Curve Segment When a curve segment is selected (with the Tangelt Tool/Select Curve), Delete Curve Segment deletes it. Closed curves will be opened and open curves will be split.
    PeakP Makes all selected control-points peak. When a curve segment is selected (with the Tangelt Tool/Select Curve) only the selected segment's curve will be changed.
    RoundO Makes all selected control-points round. When a curve segment is selected (with the Tangelt Tool/Select Curve) only the selected segment's curve will be changed.
    Clone Selected PointsC All selected control-points with at least one neighbor selected will be cloned (only curves will be cloned). The original control-points become deselected and the cloned ones selected. You can't see the result of the clone operation until you move the (now selected) clones.
    Extrude ToolE Extrude first clones the selected control-points (see Clone Selected Points). It then interconnects the original control-points with the cloned ones by adding a new curve or appends the clones to an existing curve (JPatch tries it's best to guess whether it should make a new curve or append to an existing one).
    Lathe ToolL This tool takes 2D curves and generates 3D lathed objects. It opens a dialog asking for the number of segments and the curvature. Clicking peak will set all curves in the resulting object to peak. Clicking round will set all curves in the resulting object to round and will compute the optimum value for curvature.
    Figure 2 - Lathe Options
    Figure 3 - A curve...Figure 3 - ...the lathed object

    The Popup Menu

    Clicking the right mouse button in a view will show the Popup Menu:

    Edit
    UndoUndoes the last operation
    RedoRedoes the last "undo" if no other change has been made.
    View
    Here you can change between front, back, left, right, top, bottom and birds eye view.
    Layer
    Active LayerHere you can select the "active" layer (the layer on which new objects will be added).
    Visible LayersHere you can choose which layer should be visible and which not. All makes all layers visible, none makes all invisible and invert inverts vi"sibility of all layers. Only control-points on visible layers can be selected!
    Grid
    ShowShows a grid in all projections except birds eye
    SnapEnables grid-snapping in all projections except birds eye.
    Set SpacingSets the grid spacing (to a float value).
    Show
    Here you can toggle control-point and curves display
    Selection
    Here you can select all control-points, all on the active layer or unselect all control-points, invert the selection, delete selected points, detach selected points or move the selected control-points to a different layer
    Background Image
    Rotoscope Background Image:
    This menu is only available in front/back/top/bottom or side view (not in Bird's Eye view). Set will open a file-chooser, select the image you want to be displayed. Use the Display checkbox to show/hide the image, Scale to scale and Translate to move it.