TheGameCreators - CodeBase - 3d camera scrolling around an object and turret pointing code

Category: 3D Maths

Version: 1.0

Information

Uploaded: 22nd Feb 2004 07:49

Modified: 1st Jan 1970 01:00

Author: Philip

Summary

The attached code came out of the following thread: http://darkbasicpro.thegamecreators.com/?m=forum_view&t=25644&b=7 Its code produced by Final Epsilon and myself. Basically its code which makes a turret object (a cube in this case) point at another object (a sphere in this case). The spherical aiming object can be moved by the mouse and keyboard. The code also contains Final Epsilon's rather good 3d camera scrolling routine using a 3d spherical coordinate system.

Full Description

DarkBASIC Professional Source Code

` This code was downloaded from The Game Creators

` It is reproduced here with full permission

` http://www.thegamecreators.com

Remstart

******************************************

Turret rotation code

by Philip and Final Epsilon

******************************************

Remend

sync on

sync rate 60

Rem PJY - lets just adjust this code for screen resolution

Rem PJY - otherwise my 1024 x 768 makes the mouse camera scroll go mental

screen_width = screen width()

screen_height = screen height()

Rem PJY - make a cube to act as the turret

make object cube 1, 50

position object 1, 0, 0, 0

color object 1, rgb(200, 200, 200)

set object light 1, 1

set object ambient 1, 0

Rem PJY - make a little sphere to act as the turret's aiming device

make object sphere 2, 10, 10, 10

position object 2, 0, 30, 30

color object 2, rgb(200, 150, 100)

set object light 2, 1

set object ambient 2, 0

Rem PJY - end insert sphere.

Rem PJY - make a red box to act as the world's Y axis

make object box 3, 5, 400, 5

position object 3, 0, 0, 0

Rem PJY - colour Y axis red

color object 1, rgb(212,061,026)

set object light 3, 1

set object ambient 3, 1

Rem PJY - make a blue box to act as the world's X axis

make object box 4, 400, 5, 5

position object 4, 0, 0, 0

Rem PJY - colour X axis blue

color object 4, rgb(000,000,255)

set object light 4, 1

set object ambient 4, 1

Rem PJY - make a green box to act as the world's Z axis

make object box 5, 5, 5, 400

position object 5, 0, 0, 0

Rem PJY - colour Z axis green

color object 5, rgb(000,255,000)

set object light 5, 1

set object ambient 5, 0

Rem PJY - make all the text red

ink rgb(212, 061, 026), rgb(212, 061, 026)

Rem PJY - initialise camera movement code

x# = 0

y# = 0

z# = -400

position camera x#, y#, z#

point camera 0, 0, 0, 0

bearing# = 0

azimuth# = 0

distance# = 300

mousedistancez# = 1000

Rem PJY - make a randomized matrix to represent "ground"

make matrix 1, 1000, 1000, 50, 50

position matrix 1, -500, 0, -500

randomize matrix 1, 20

update matrix 1

Rem PJY - make some vectors - they are always handy!

one = 1

two = 2

three = 3

four = 4

five = 5

six = 6

null = make vector3(one)

null = make vector3(two)

null = make vector3(three)

null = make vector3(four)

null = make vector3(five)

null = make vector3(six)

Rem PJY - reset camera scroll variables

mouse_x# = 0

mouse_y# = 0

Rem PJY - Camera control (and scrolling) code

if mousey() <= 50 then mouse_y# = -2

if mousex() <= 50 then mouse_x# = -2

if mousey() >= (screen_height - 50) then mouse_y# = 2

if mousex() >= (screen_width - 50) then mouse_x# = 2

bearing# = wrapvalue(bearing# - mouse_x#)

azimuth# = wrapvalue(azimuth# - mouse_y#)

x# = distance# * sin(azimuth#) * cos(bearing#)

z# = distance# * sin(azimuth#) * sin(bearing#)

y# = distance# * cos(azimuth#)

position camera x#, y#, z#

point camera 0, 0, 0, 0

Rem PJY - display some useful variables

set cursor 0, 0

print "Up key to make target object move away from camera"

print "Down key to make target object move towards the camera"

print "Click to place object at new world X Y Z coords"

print "Blue is X axis, Red (ok, grey) is Y axis, Green is Z axis"

print ""

print "Camera bearing: ";bearing#

print "Camera azimuth: ";azimuth#

print "Camera distance: ";distance#

print "Mouse X: ";mousex()

print "Mouse Y: ";mousey()

Rem PJY - code to pick the aiming object and move it

pick_test = pick object(mousex(), mousey(), 2, 2)

set vector3 one, object position x(2), object position y(2), object position z(2)

set vector3 two, camera position x(0), camera position y(0), camera position z(0)

subtract vector3 three, one, two

length# = length vector3(three)

print "Obj 2 x: ";object position x(2);" y: ";object position y(2);" z: ";object position z(2)

print "Camera x: ";camera position x(0);" y: ";camera position y(0);" z: ";camera position z(0)

print "Camera to Target Obj vector x: ";x vector3(three);" y: ";y vector3(three);" z: ";z vector3(three)

Rem PJY - if upkey is pressed move the aiming object away from the camera

if upkey() = 1 AND length# > 10 AND length# < 800

temp_x# = x vector3(three) * 1.1

temp_y# = y vector3(three) * 1.1

temp_z# = z vector3(three) * 1.1

set vector3 five, temp_x#, temp_y#, temp_z#

add vector3 four, two, five

endif

Rem PJY - if downkey is pressed move the aiming object towards the camera

if downkey() = 1 AND length# > 50 AND length# <= 1000

temp_x# = x vector3(three) * 0.9

temp_y# = y vector3(three) * 0.9

temp_z# = z vector3(three) * 0.9

set vector3 five, temp_x#, temp_y#, temp_z#

add vector3 four, two, five

endif

Rem PJY - if mouseclick then place aiming object in 3d world

if mouseclick() = 1

pick screen mousex(), mousey(), length#

pick_x# = get pick vector x()

pick_y# = get pick vector y()

pick_z# = get pick vector z()

set vector3 five, pick_x#, pick_y#, pick_z#

add vector3 four, two, five

endif

Rem PJY - position aiming object at the new coordinates

position object 2, x vector3(four), y vector3(four), z vector3(four)

Rem PJY - calculate new orientation of cube

Rem PJY - first get the azimuth angle

set vector3 six, object position x(1), object position y(1), object position z(1)

subtract vector3 three, six, one

normalize vector3 three, three

set vector3 two, 0, 1, 0

angle_y# = acos(dot product vector3(three, two))

print "Angle Y: ";angle_y#

Rem PJY - secondly get the rotation angle

temp_x1# = object position x(1)

temp_x2# = object position x(2)

temp_z1# = object position z(1)

temp_z2# = object position z(2)

temp_x# = temp_x1# - temp_x2#

temp_z# = temp_z1# - temp_z2#

ang1# = atanfull(temp_x#, temp_z#)

if ang1# < 0 then ang1# = 360.0 + ang1#

Rem PJY - finally rotate the cube to make it point at the aiming object

yrotate object 1, ang1#

xrotate object 1, angle_y#

print "Angle on X/Z plane: ";ang1#

sync

loop

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Author Name:	Philip
CodeBase Entries:	11

CodeBase - 3d camera scrolling around an object and turret pointing code

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DarkBASIC Professional Source Code

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