3D graphics and VR

Date: Thu Mar (22:02)              Number: 151
From: MADRIUS #131 @5092           Refer#: NONE
  To:                               Recvd: YES 
Subj: 3D graphics and VR             Conf: (5) The Edge-F

Noone seems to be too interested in our project on Virtual Reality, but I will continue posting the information around it in case someone out there is silently writing all this stuff and figuring out stuff on their own. Please, if anyone else out there is working on a project and has a breakthrough, post it! I want to collaborate my efforts with as many people as I possibly can. I found out some information on graphically representing 3-dimensional points that should help a whole lot. First of all, I need two arrays for some lineart drawings I'm working on. The first array is P. The first dimension is the number assigned to the point, from (for the purposes of this example) 0-500. The second dimension of P is from 0-2, and is the x,y,or z coordinate. For example, P(1,0) would be the x coordinate of point 1, P(1,1) would be the y coord for point 1, P(1,2) would be the Z. P(2,1) would be the y coord for point 2, and so on. The second array is also two dimensions, the first being the number of a line, the second being either endpoint 1 or 2 for the line. i.e. Line 1 would go from the point # stored in L(1,0) to the point # in L(1,1). So to draw line 1, we would need to set the variable A to L(1,0) and the variable B to L(1,1). Then draw a line from (P(A,0),P(A,1),P(A,2)) to (P(B,0),P(B,1),P(B,2)). Next we come to the problem of where to display a point with X,Y,and Z coordinates on a screen that only uses X and Y coordinates. I found a formula that does this exact thing...There's a diagram that explains it, but it's kind of hard to draw it out in ASCII, so I will just list the formula, play around with it yourself and see how it works in proportion. Maybe I will draw out the diagram as a .GIF and upload it here...The formula is: Y*D1 new Y=------ D1+Z Where Y and Z are the Y and Z coords of the point, and D1 is the distance of the user's eye from the screen. Now for some ideas on translation. --Shifting: Really easy, just add or subtract from the X,Y,or Z coordinates of each point to find the new location, whether you want to shift up, down, left, right, toward you, or away from you. --Scaling: Move each point away from the center point of the object --Rotation: here's some formulas for rotation about each axis (t=angle of rotation.) Rotation about Z-axis X' = X * COS(T) - Y * SIN(T) Y' = Y * COS(T) + X * SIN(T) Z' = Z Rotation about Y-axis X' = X * COS(T) - Z * SIN(T) Y' = Y Z' = Z * COS(T) + X * SIN(T) Rotation about X-axis X' = X Y' = Y * COS(T) - Z * SIN(T) Z' = Z * COS(T) + Y * SIN(T) We now have all kinds of information for representing and changing 3D objects. Try playing around with these in your programs and see what you come up with... C'mon people, we need to start working on this... Keep VR out of the hands of government and corporate pigs who have a monopoly on other technology and will definitely charge a high price for this one! If we can develop a VR program and maybe a computer around it, we can all have it, without laws or restrictions! MADrius and Drahgon :)
Outer Court
Echo Basic Postings

Books at Amazon:

Back to BASIC: The History, Corruption, and Future of the Language

Hackers: Heroes of the Computer Revolution (including Tiny BASIC)

Go to: The Story of the Math Majors, Bridge Players, Engineers, Chess Wizards, Scientists and Iconoclasts who were the Hero Programmers of the Software Revolution

The Advent of the Algorithm: The Idea that Rules the World

Moths in the Machine: The Power and Perils of Programming

Mastering Visual Basic .NET