[SOLVED] Sprite-character rotation-movement GDScript

Schuster

Hi, I have a sprite-character and I need some advice-help with a script on the character. Character is the bird...top-down camera follow, I modified the script of the demo but I need to make the character, turning on, A key-to the left and D key-to the right. next- mouse left click-LMB -move forward but not at a constant speed but the inertia (the bird slowly stops) and S key-like landing-a slow stop. ...rotation to the left and right-90 degrees, the bird flies in the direction of rotation. Thanks for the help <img alt="" height="20">

jack

Can you share your existing script? (Which demo is it modified from, also?)

Schuster

Hi,This script I use, is from the Isometric Game demo.[code]extends KinematicBody2D# This is a simple collision demo showing how# the kinematic controller works.# move() will allow to move the node, and will# always move it to a non-colliding spot,# as long as it starts from a non-colliding spot too.# Member variablesconst MOTION_SPEED = 120 # Pixels/secondconst MODE_DIRECT = 0const MODE_CONSTANT = 1func fixed_process(delta): var motion = Vector2() if (Input.is_action_pressed("move_forward")): motion += Vector2(0, -1) if (Input.is_action_pressed("move_down")): motion += Vector2(0, 1) if (Input.is_action_pressed("move_left")):        motion += Vector2(-1, 0) if (Input.is_action_pressed("move_right")): motion += Vector2(1, 0) motion = motion.normalized()MOTION_SPEEDdelta motion = move(motion) # Make character slide nicely through the world var slide_attempts = 4 while(is_colliding() and slide_attempts > 0): motion = get_collision_normal().slide(motion) motion = move(motion) slide_attempts -= 1func ready(): set_fixed_process(true)[/code]

jack

Okay, cool.Do you have your input-mapping hooked up? If you don't, go to Project Settings -> Input Mapping and do that. You'll want to create actions with the names from your script ("move_forward", "move_left", etc) and map those to the appropriate keys. That should get your bird moving in the right directions; to make it also face the right way, you'll probably want to add rotation for the sprite, a la:[code]var sprite = find_node("Sprite")...if (Input.is_action_pressed("move_right")):    motion += Vector2(1,0)    sprite.set_rot(-90.0)[/code]

Schuster

Hi jack,Thanks...Yes, I have assigned the keys to move actions.I tried the script what you wrote but somehow does not work :(I got an error: Attempt to call function 'set_rot' in base 'null instance' on a null instance.W key - move_forward -worksS key -move_down  -worksA key -rotate_left -this errorD key -rotate_right -this error[code]extends KinematicBody2D# This is a simple collision demo showing how# the kinematic controller works.# move() will allow to move the node, and will# always move it to a non-colliding spot,# as long as it starts from a non-colliding spot too.# Member variablesvar sprite = find_node("player")# Member constconst MOTION_SPEED = 120 # Pixels/secondconst MODE_DIRECT = 0const MODE_CONSTANT = 1func fixed_process(delta): var motion = Vector2() if (Input.is_action_pressed("move_forward")): motion += Vector2(0, -1) if (Input.is_action_pressed("move_down")): motion += Vector2(0, 1) if (Input.is_action_pressed("rotate_left")): motion += Vector2(-1, 0) sprite.set_rot(90.0) if (Input.is_action_pressed("rotate_right")): motion += Vector2(1,0) sprite.set_rot(-90.0)    motion = motion.normalized()MOTION_SPEEDdelta motion = move(motion) # Make character slide nicely through the world var slide_attempts = 4 while(is_colliding() and slide_attempts > 0): motion = get_collision_normal().slide(motion) motion = move(motion) slide_attempts -= 1func ready(): set_fixed_process(true)[/code]

Battery

I think that's because there's no object named [tt]sprite[/tt] in your project (from looking at the image you posted of your scene tree) so it will always return null.If you wanna rotate your whole character you could just go:[code] if (Input.is_action_pressed("rotate_right")): motion += Vector2(1,0) set_rot(-90.0) [/code]Alternatively, if you just wanted to rotate your bird sprite you could use:[code] if (Input.is_action_pressed("rotate_right")): motion += Vector2(1,0) get_node("bird").set_rot(-90.0) [/code]Hope this helps!

Schuster

Thanks a lot, now it works :)...just would somehow enhance that sprite rotated more slowly/softly?Script:[code]extends KinematicBody2D# This is a simple collision demo showing how# the kinematic controller works.# move() will allow to move the node, and will# always move it to a non-colliding spot,# as long as it starts from a non-colliding spot too.# Member variablesvar sprite = find_node("bird")# Member constconst MOTION_SPEED = 120 # Pixels/secondconst MODE_DIRECT = 0const MODE_CONSTANT = 1func fixed_process(delta): var motion = Vector2() var rotated = Vector2() if (Input.is_action_pressed("move_forward")): motion += Vector2(0,-1) get_node("sprite").set_rot(0.0) if (Input.is_action_pressed("move_down")): motion += Vector2(0,1) get_node("sprite").set_rot(135.0) if (Input.is_action_pressed("rotate_left")): motion += Vector2(-1,0) get_node("sprite").set_rot(-5.0) if (Input.is_action_pressed("rotate_right")): motion += Vector2(1,0) get_node("sprite").set_rot(5.0) motion = motion.normalized()MOTION_SPEEDdelta motion = move(motion) # Make character slide nicely through the world var slide_attempts = 4 while(is_colliding() and slide_attempts > 0): motion = get_collision_normal().slide(motion) motion = move(motion) slide_attempts -= 1func ready(): set_fixed_process(true)[/code]

Battery

First off, looking at your code I think you're confusing radians with degrees (which I did in my first post!). [tt]set_rot()[/tt] takes the angle in radians. Passing 135 radians to [tt]set_rot()[/tt] when the turn is instanteous is no big deal. But once you slow the turn down, what you've got is 21.4 turns before the sprite settles at the desired orientation if rotating from 0.0 (one turn being 2PI: 135 / 2PI = 21.4859). If you want to use degrees rather than radians you can use [tt]set_rotd([/tt]) and [tt]get_rotd()[/tt]. Since Godot tries to use artist friendly units you'd think [tt]set_rot()[/tt] would be in degrees with the option to use radians. I guess it's the other way round as programmers expect to work with radians, so it's easy to thrown by this. Anyway, Interpolating rotation in 2D is a real pain, thanks to angles wrapping round at 2PI and trying to find the shortest direction to turn in. Here's my solution:[code]extends KinematicBody2D# This is a simple collision demo showing how# the kinematic controller works.# move() will allow to move the node, and will# always move it to a non-colliding spot,# as long as it starts from a non-colliding spot too.# Member variablesvar sprite = find_node("bird")# Member constconst MOTION_SPEED = 120 # Pixels/secondconst MODE_DIRECT = 0const MODE_CONSTANT = 1const ROT_SMOOTHING = 0.1 func lerp_angle(from, to, t): if abs(to - from) > 180: to = -(360 - to) return lerp(from, to, t) func fixed_process(delta): var motion = Vector2() var rotated = Vector2() if (Input.is_action_pressed("move_forward")): motion += Vector2(0,-1) var rot = get_node("sprite").get_rotd() var new_rot = lerp_angle(rot, 0.0, ROT_SMOOTHING) get_node("sprite").set_rotd(new_rot) if (Input.is_action_pressed("move_down")): motion += Vector2(0,1) var rot = get_node("sprite").get_rotd() var new_rot = lerp_angle(rot, 180.0, ROT_SMOOTHING) get_node("sprite").set_rotd(new_rot) if (Input.is_action_pressed("rotate_left")): motion += Vector2(-1,0) var rot = get_node("sprite").get_rotd() var new_rot = lerp_angle(rot, 90.0, ROT_SMOOTHING) get_node("sprite").set_rotd(new_rot) if (Input.is_action_pressed("rotate_right")): motion += Vector2(1,0) var rot = get_node("sprite").get_rotd() var new_rot = lerp_angle(rot, -90.0, ROT_SMOOTHING) get_node("sprite").set_rotd(new_rot) motion = motion.normalized()MOTION_SPEEDdelta motion = move(motion) # Make character slide nicely through the world var slide_attempts = 4 while(is_colliding() and slide_attempts > 0): motion = get_collision_normal().slide(motion) motion = move(motion) slide_attempts -= 1func ready(): set_fixed_process(true)[/code]There are a couple of cases where this doesn't work well (switching quickly between diagonal movements in opposite directions). The best solution is using complex numbers (2D quaterions, spinors), but this a bit above my maths knowledge. Hope this helps!  :)

Schuster

Great, thanks a lot, it works great, the rotation is now slower and it looks better.I edited my previous script where I had those 135 radians and now also works :)...as follows-0.0-forward/up and down/back 3.14 but works :DThanks for your Big help!![code]extends KinematicBody2D# This is a simple collision demo showing how# the kinematic controller works.# move() will allow to move the node, and will# always move it to a non-colliding spot,# as long as it starts from a non-colliding spot too.# Member variablesvar sprite = find_node("bird")# Member constconst MOTION_SPEED = 250 # Pixels/secondconst MODE_DIRECT = 0const MODE_CONSTANT = 1const MODE_SMOOTH = 2const ROTATION_SPEED = 2func fixed_process(delta): var motion = Vector2() var rotated = Vector2() if (Input.is_action_pressed("move_forward")): motion += Vector2(0,-1) get_node("sprite").set_rot(0.0) if (Input.is_action_pressed("move_down")): motion += Vector2(0,1) get_node("sprite").set_rot(3.14) if (Input.is_action_pressed("rotate_left")): motion += Vector2(-1,0) get_node("sprite").set_rot(-300.0) if (Input.is_action_pressed("rotate_right")): motion += Vector2(1,0) get_node("sprite").set_rot(300.0) motion = motion.normalized()MOTION_SPEEDdelta motion = move(motion) # Make character slide nicely through the world var slide_attempts = 2 while(is_colliding() and slide_attempts > 0): motion = get_collision_normal().slide(motion) motion = move(motion) slide_attempts -= 1func ready(): set_fixed_process(true)[/code]

Battery

No worries! Happy to help!  :DGoogle can convert degrees to radians for ya. Godot also has [tt]deg2rad()[/tt] and [tt]rad2deg()[/tt] if you ever need to make the conversion in a script.