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Escher

Nice to have you here! With Escher you will create visually rich designs directly on the geometry of 3D meshes. The idea behind Escher is very simple: A 3D mesh is made of triangles. To model a design on its geometry, you replace its every triangle with a pattern. This pattern is not a texture, but an another collection of triangles. Thus the integrity of the resultant mesh is maintained while the arrangement of its triangles suggest a design to the eye. This idea is called: Geometric Substitution. It was pioneered by Dr. Andrew Glassner (now) of Microsoft Graphics Research Group.

REQUIREMENTS:

Escher is a VRML + Java applet and requires the following to run:

Browser ISSUES:

If you have to reload the applet, do Shift-Reload instead of just hitting the Reload button. Also, if you leave this page and come back to it, you have a good chance of crashing your browser! Sort of a one way ticket!

The WORK:

Houston, We need Cosmo Player to Run Demo

User GUIDE:

This applet has two windows.  The window with the black background (the VRML Window) belongs to Cosmo Player.  The  window with the gray background (the Applet Window) belongs to the applet.  You will draw a pattern from scratch or select a pre-defined pattern in the Applet Window.  The applet will model the current pattern on the mesh and display it in the VRML Window.

If you scroll up this page, you can see these windows now.  Click on the VRML window and press the backslash key.  You will bring up the Cosmo Player console.  The applet sends crucial messages to this console.  Apart from the copyright, dedication and thanks watch out for the following messages:

<<< Connecting to the VRML world >>>
<<< Connection established >>>
<<< Sample Patterns Loaded >>>
<<< Sample Meshes Loaded >>>

If you have gotten this then everything went off really well.  You may close the Console now.  If not, other messages should tell you where exactly the problem was.  PLEASE contact me in that situation.

A tastefully colored Tetrahedron should now be rotating in the VRML window.  You can replace it with a different mesh by selecting it from the Choose Mesh combo box.  The following meshes are available for your perusal:   Octahedron, Icosahedron, Dodecahedron, Cube, Sphere and the CG sex symbol : Teapot

There are two ways to model a pattern on the Tetrahedron.  First, you could draw the pattern over the white reference triangle (the Board) in the Applet Window using Create Triangle, Move Vertex and Delete Triangle tools.  The other (easy) way is to choose one from the list of pre-defined patterns.  So, click the Choose Pattern combo box and select the  pattern named Wheel-I.  You will now see the pattern modeled on the Tetrahedron in the VRML window.    If you wish to model it on an Octahedron instead, choose Octahedron from the Choose Mesh combo box and you will find it modeled on the Octahedron as well.

From the Apply Pattern combo box, you tell the applet how many times to recursively model the pattern on the mesh.  By default, the applet models the pattern Once.  Twice is an another alternative.  If you choose Zero Times, the pattern will not be modeled at all.   Note that after every application of the pattern, the number of triangles in the mesh increases sharply.  For intrinsically heavy meshes like the Teapot, you might not want to venture beyond the Once option.  Coming back to our example,  boldly apply Wheel-I Once, Twice, and Zero times on the Tetrahedron and see what happens.

When you select a pattern from the Choose Pattern combo box, the applet discards any pattern that was already modeled on the mesh.   That is, it models the selected pattern on the mesh afresh.  You might instead want to model Wheel-I first and follow it up with Benz-I.  In that case, you use the New Pattern Layer button.  You select the pattern Wheel-I, hit the New Pattern Layer button and select Benz-I.    What would you do if you wanted to apply Wheel-I twice and follow it up with Benz-I ?  You first bang the Kill Other Layers button to kill existing layers, choose Wheel-I, choose Twice from the Apply Pattern combo, bang the New Pattern Layer button and choose Benz-I. 

Any pattern you select from the Choose Pattern combo box, is copied onto the Board and is available for editing.  Three tools help you in this process: Create Triangle, Move Vertex and Delete Triangle.  Note that the selected pattern is not modified, only a copy of it is modified.  So you can revert to the original pattern as often as you like.   There is no Delete All Triangles tool, instead select the pattern Blank from the Choose Pattern combo box. 

As you modify the triangles in the pattern, you will notice that the pattern is dynamically modeled on the mesh. However, this could consume a lot of CPU cycles when the initial mesh is very heavy.  You could stall real-time update by selecting Zero Times from the Apply Pattern combo box.  Once you have the pattern you like, you could select Once or Twice  from the Apply Pattern combo box to model it on the mesh.  

Three more controls affect how the mesh is presented in the VRML window: 

You can select the texture to apply on the mesh from The Mesh Texture Is combo box. These textures are not procedural, but small GIF images. I generated them in Adobe Photoshop using the Gradient Fill tool. Apart from providing good looks for our mesh, they prove that texture mapping is not a problem at all in the case of pattern-modeled meshes.

The Rotate Mesh About combo box determines whether the mesh spins about the X, Y or Z axis.  If you are allergic to constant rotation, Stop Rotation is for you.

The See Through Mesh is self-explanatory.  By default you can see through the mesh in the VRML window. Turning it off reduces visual clutter (but many people like this clutter!) and increases frame rate.

And finally, you can watch your mesh from two Viewpoints. One is the default view called Home. The other takes you Inside the mesh with the design rolling all over you. Both these viewpoints are accessible from the VRML window.

Enjoy!

Things To TRY:

I love the Teapot! All of these experiments are my favorites. I'm sure if you play long enough, you will find your own. Before we begin, make sure you bang the Kill Other Layers button and keep the Apply Pattern combo box pointing to Once. We should do this because the Teapot has got a number of triangles and applying any pattern is only going to increase it (except Shrink -- can you figure out why?)

Liked the results? Try changing the textures! You'll love it!

The T I T A N I C:

Yes, who has not been influenced by James Cameroon's Titanic :-) I have a pattern that iconises (spoofs?) the Titanic. Its available from the Choose Pattern combo box. Feel free to model it on any mesh you like :-)


DEDICATION:

I dedicate this work to my mother, my father, my sister and my friend (who wishes to be identified at this time as) The Luse

About ESCHER:

Escher is a personal work and I am solely responsible for everything related to it and not my company EFX. Of course, I am very grateful to Mr. Sai Prasad, Director - EFX for fostering personal projects while in professional service!

About ME:

My name is Jagannathan Sampath, a Production Software Engineer with EFX, Chennai, India. I am committed to developing software that helps create visual effects for movies, television and games. I love procedural modeling and animation, late night VRML + Java programming, dancing and pantomime.

I also have a web page that contains demos of other projects you might like. Please point your browser to:

http://members.tripod.com/sjagannathan/

Contact INFORMATION:

Jagannathan Sampath
F14, HIG Flats,
Anna Main Road,
KK Nagar,
Chennai - 600 078
Tamil Nadu
INDIA

eMAIL : sjagan@hotmail.com

pHONE : +91-044-4890321

web PAGE : http://members.tripod.com/sjagannathan/