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GUI sort of thing help

edited April 2014 in Questions Posts: 22

I can't seem to figure out how to use perspective and ortho correctly. I have a 3d world, but I'm trying to add in a CAMERA as the background, so it acts like an agumented reality game.

background(0, 0, 0, 0)
local mat = matrix()
local dxa = RotationRate.x
local dya = RotationRate.y
local dza = RotationRate.z
mat = mat:rotate(dza, dirz.x, dirz.y, dirz.z)
mat = mat:rotate(dya, diry.x, diry.y, diry.z)
mat = mat:rotate(dxa, dirx.x, dirx.y, dirx.z)
dirx = mult(mat, dirx)
diry = mult(mat, diry)
dirz = mult(mat, dirz)
local x = dirz.x * d
local y = dirz.y * d
local z = dirz.z * d
camera(x, y, z, 0, 0, 0, diry.x, diry.y, diry.z)

This is a section of the code. The sprite with the CAMERA in it, is also in the 3d world. Which I'm trying to fix. But I can't seem to do it.


  • IgnatzIgnatz Mod
    Posts: 5,396

    @Leviathan - the way you are doing rotation - changing camera orientation - seems rather strange to me (unless you know what you are doing of course!).

    I've written a partial ebook on 3D graphics in Codea here, which covers the basics in Codea.pdf

    plus many other 3D posts

    btw, perspective turns on 3D drawing, ortho turns it off, basically

  • Posts: 1,976

    I think some of the problem is the order you're drawing in. There are some other problems in the parameters, too. Something like this should be better:

    function setup()
        angle = 0
        FieldOfView = 45
        screen = image(WIDTH, HEIGHT)
    function draw()
        sprite(CAMERA, WIDTH / 2, HEIGHT / 2)
        background(0, 0, 0, 0)
        angle = angle + RotationRate.y / math.abs(Gravity.y)
        local x, y, z = math.sin(math.rad(angle)) * 200, Gravity.z * 200, math.cos(math.rad(angle)) * 200
        camera(0, 0, 0, x, y, z, 0, 1, 0)
        translate(0, 0, 200)
        sprite("Planet Cute:Character Boy")
        sprite(screen, WIDTH / 2, HEIGHT / 2)

    I think I got it. How's that? Runs fine for me.

    @Ignatz Perspective adds in distortion of the mesh for the vertices to be smaller depending on their distance, ortho does none of that. Ortho supports 3D. You'd need to reset the camera too for it to appear as if you were drawing in 2D.

  • Posts: 22

    Oh my gosh thank you! I read the ebooks and tried out your code, it works perfectly. Thank you!

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