by Sascha Ledinsky
NEWS:
15 Dec 2005
JPatch 0.5.2 (development version) has been released

25 Nov 2005
The JPatch homepage has moved to a new host. Outages are (hopefully) a thing of the past.

14 Oct 2005
JPatch 0.5.1 (development version) has been released

9 May 2005
JPatch 0.4 PREVIEW 1 has been released

LINKS:
POV-Ray Internet Movie Project The Aqsis renderer

Firefox 2 Get Thunderbird! Play Ogg

Frequently asked questions

1. General

1.1 Why was JPatch written in Java?
1.2 But isn't Java slow?
1.3 Can I use JPatch to evaluate commercial producs, such as Hash Inc.'s Animation:Master?
1.4 Are there tutorials available for JPatch?

2. Modeling

2.1 How can I insert a new control-point on an existing spline?

3. Rendering

3.1 How can I add lightsources and a camera to the scene?

1. General

1.1 Why was JPatch written in Java?

When I started to work on JPatch I was new to object oriented programming, and Java was easier to learn than, for example, C++. I wanted JPatch to run on at least Windows and Linux platforms, so Java's write-once-run-everywhere approach came in handy.

1.2 But isn't Java slow?

No.

This old stereotype was true in the early days of Java, when the Java Bytecode was interpreted by the JVM (Java Virtual Machine). Meanwhile, all modern JVMs use JIT (Just In Time) compilation. As the JIT compiler knows exactly on which CPU model the JVM runs, which classes are loaded, etc., it is able to generate highly optimized machine code for the platform it runs on. Most Java code will run just as fast as analogical C++ code.

The latest (development) versions of JPatch also utilize OpenGL, and thus are able to benefit from hardware accelerated 3D rendering provided by most modern graphics cards.

1.3 Can I use JPatch to evaluate commercial producs, such as Hash Inc.'s Animation:Master?

No way!

Neither I nor JPatch are in any way related to Hash Inc. or Animation:Master. If you're interested in Animation:Master, please inform yourself on Hash Inc.'s website.
JPatch uses spline based modeling, as does e.g. sPatch, hama-patch and Animation:Master. That's why it can import sPatch and Animation:Master model files (geometry only), just as most polygon or SDS modelers can import .obj or .3ds files, for example.

Let's stay down-to-earth: JPatch is still in an early state of development, Animation:Master on the other hand is, for what it's worth, a mature 3D modeling, rendering and animation package.

1.4 Are there tutorials available for JPatch?

Yes, there's some documentation and tutorials available in the Wiki. There are also some tutorials for other spline/patch based modelers available on the internat - they might possibly be applicable for JPatch too.

2. Modeling

2.1 How can I insert a new control-point on an existing spline?

Select the curve-segment you'd like to insert the new point by clicking on a controlpoint and pressing the TAB key until the curve-segment becomes highlighted. Now press the INSERT key to insert a new controlpoint.

3. Rendering

3.1 How can I add lightsources and a camera to the scene?

In the modeler, you can't. If you export a JPatch model from the modeler, you'd need to import it into an existing scene. Here are two simple scene files that define some lightsources, a camera and load a JPatch model (you'll have to edit them and enter the path to your model file):

You can of course manipulate the camera and lightsources in animations. Check out the JPatch 0.4 animator documentation.

Screenshots [click on images to enlarge]:

A screenshot of the latest development version (May. 2006)


A screenshot of the development version (Nov. 2005)


JPatch 0.4's modeler window with 4 viewports


Working with morphs


JPatch's material editor.