View source for Eng:How to Make a Three-Dimensional Project

{{:Eng:How to Make a Three-Dimensional Project/translate}}
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{{Wiki Standards|Too short, little explanation.}}

{{Note|This tutorial is recommended for a bit more experienced [[Eng:Scratchers|Scratchers]] due to its intricacy.}}

== What is a 3D environment?==


A 3D environment is a place that involves the common X and Y axes, as well as the additional Z axis. 
The Z axis is a Cartesian coordinate, much like the X and Y axes, but the Z axis usually is the axis for depth. In real life, the Z axis exists, but in [[Eng:Scratch|Scratch]], it does not. We can incorporate size and movement that causes an illusion of depth.

== Example using size to create a 3D effect==
This [[Eng:script|script]] uses [[Eng:sprites|sprites]] and size change for depth perception:

<scratchblocks>
when green flag clicked
set [scroll z v] to [60]
set [scroll y v] to [0]
set [scroll x v] to [-30]
forever
  set size to ((scroll z) + ((40) * (0)))%
  set x to ((scroll x) + ((480) * (0)))
  set y to ((scroll y) + ((360) * (0)))
  if <key [up arrow v] pressed?> then
    change [scroll z v] by ((size) / (45))
    change [scroll x v] by ((x position) / (55))
  end
  if <key [down arrow v] pressed?> then
    change [scroll z v] by ((size) / (-45))
    change [scroll x v] by ((x position) / (-55))
  end
  if <key [left arrow v] pressed?> then
    change [scroll x v] by ((size) / (55))
  end
  if <key [right arrow v] pressed?> then
    change [scroll x v] by ((size) / (-55))
  end
  if < <(scroll z) < [20]> or <(scroll z) > [217]> > then
    hide
  else
    show
  end
</scratchblocks>
The "scroll x" and "scroll y" variables' value can be changed so the sprite's position can be changed. 
The "scroll z" variable is rather special. It '''does not '''change the sprite's position, but it changes The size of the sprite.

This method of 3D scripting is very rudimentary, and it does not involve any collision detection, and it would not apply to a moving object. 

This is one of the ways you can make the illusion of 3D. [[Eng:Scratch|Scratch]] doesn't allow you to make three dimensional games, but it allows you to make the illusion of one. The X axis is the [[Eng:sprites|sprites]] position from left to right. The Y axis is the position from top to bottom, and the Z axis is the [[Eng:sprites|sprites]] size, allowing you to make the sprite small or large. As said in the beginning of this article, we can always incorporate size and movement to create the 3D illusion. If you stroll down a street, you will notice that the farther the things are, the smaller they look. If you put this same principle in video games, you will get a 3D effect.
A [[Eng:Raycaster|Raycaster]] is a more efficient way of 3D in Scratch.

==Example using pen and layering==
This is a slightly more efficient way of making a 3D illusion. This technique uses layering and stamping. Here is the [[Eng:script|script]]:
<scratchblocks>
when flag clicked
forever
  clear
  go to x(0) y(0)
  stamp
  change y by(2)
  stamp
  change y by(2)
  stamp
  change y by(2)
  stamp
  change y by(2)
  stamp
  change y by(2)
  stamp
  change y by(2)
  stamp
end
when green flag clicked
forever
  point towards [mouse-pointer v]
end
</scratchblocks>
 
This method does not use size to create the 3D effect. It changes the position of the sprite and [[Eng:stamps|stamps]] the sprite on the background. This makes several copies of the same sprite, in different positions. This creates a 3D effect.


==See Also==
*[[Eng:Raycaster|Raycaster]]
*[[Eng:Three Dimensional Project|Three Dimensional Project]]
*[[Eng:Sprite-Based Raycaster Tutorial|Sprite-Based Raycaster Tutorial]]
 
[[Category:Scripting Tutorials|Three-Dimensional Project]]
[[Category:How To Pages|Make a Three-Dimensional Project]]