Object rotation:

rotatedX = x * cos(directoin) - y * sin(direction)
rotatedY = x * sin(direction) + y * cos(direction)

Camera rotation:

rotatedX = z * sin(ry) + x * cos(ry)
rotatedZ = z * cos(ry) - x * sin(ry)
rotatedY = rotatedZ * sin(rx) + y * cos(rx)
rotatedZ = rotatezZ * cos(rx) - y * sin(rx)

NormalFradOfficial wrote:

Simple; Talk To Griffpatch.

s714655 wrote:

NormalFradOfficial wrote:

Simple; Talk To Griffpatch.

Nice answer! ig. Not sure if griffpatch will see the comment let alone read it, you know how many messages he has?

player3676 wrote:

just add this script

NormalFradOfficial wrote:

player3676 wrote:

just add this script

s714655 wrote:

There are many ways to do 3d in scratch. The main ways are clones/sprites, raycasting(pen), and object rendering(pen and mostly uses lines or Tri fillers). You can go to a three dementional point with screenx = x / z and screeny = y / z. Its good to have a focal length wich makes the z value not look as bad on screen (idk how to explain but it kinda stretches the points). I use x * (focal / z) and y * (focal / z) or set z to focal / z before doing x * z and y * z. You can make a custom block for this and the size if your using clones is 100 * (focal / z).

There are two types of rotation that I use; object rotation, and camera rotation. Object rotation is like having an object as a model and rotating the model but camera rotation rotates the world around the camera.

Object rotation:

rotatedX = x * cos(directoin) - y * sin(direction)
rotatedY = x * sin(direction) + y * cos(direction)

I don't use object rotation a lot in games…

rx = rotation X of camera (up and down)
ry = rotation Y of camera (left and right)
(you don't need a z rotation for game cameras so this will do)

Camera rotation:

rotatedX = z * sin(ry) + x * cos(ry)
rotatedZ = z * cos(ry) - x * sin(ry)
rotatedY = rotatedZ * sin(rx) + y * cos(rx)
rotatedZ = rotatezZ * cos(rx) - y * sin(rx)

I forgot to mention that the object rotation thing only rotates around the z axis, to rotate around the other axes you can swap out the x and y for the “horizontal” and “vertical” cords of that axis. x = yz, y = xz, z = xy.

For camera rotation you want to move the x y z points by - camera x y z before you rotate then project it onto the screen. The rotation means that no matter the camera rotation, z will be infront of the camera. Because of this if the z of the point is less than 0 than its behind the camera, you can also create a near plane to clip it when its close to the camera. You can set the near plane variable to anything but its perferred to be (I think) around 1 - 100 for scratch. I use 30 - 50.

If you want a little optimisation you can check its distance to the camera before rotating:

x = x - camera
y = y - camera
z = z - camera
distance = sqrt(x^2 + y^2 + z^2)
if(distance > near && distance < far) then
rotate(x, y, z) // camera already been subtracted from point above
if(rotatedz > 0) then
project

with this case I prefer you don't use the near for z clipping, just use 0. Use the near and far for distance clipping. The far is a number like 500 or 1000.

Those are the basics of 3d in scratch ig. If you have any questions don't hesitate to ask!