How to increase character movement velocity over time? (UPBGE)

Question

I found a 3D character controller setup online and one thing I wanted to ask is how to make movements smoother by easing velocity. Is there a way to edit the python script to make acceleration and deceleration less abrupt so that starting and stopping looks more realistic? e.g. taking half a second to reach to reach max velocity after clicking the move button. Thank you.

Answer 1

add 2 more properties to your character: speed and oldMove

you could use this script:

import bge
from bge import render

cont = bge.logic.getCurrentController()
own = cont.owner

scene = bge.logic.getCurrentScene()
empty = scene.objects["Empty"]
pointer = scene.objects["Empty.002"]

empty.worldPosition = own.worldPosition
move = 1

emptyrot = cont.actuators["rotz"]
playerRot = cont.actuators["playerRot"]
mouseMove = cont.sensors["MouseLook"]

keyboard = bge.logic.keyboard.events

W = keyboard[bge.events.WKEY]
A = keyboard[bge.events.AKEY]
S = keyboard[bge.events.SKEY]
D = keyboard[bge.events.DKEY]



if own["speed"] > 1:
    own["speed"] = 1


if W > 0:
    if own["oldMove"] == "W":
        own["speed"] += .02
    else:
        own["speed"] = 0
        own["oldMove"] = "W"
    own.alignAxisToVect(own.getVectTo(pointer)[1], 1, 0.15)
    own.applyMovement((0,own["speed"],0), True)
    own["timer"] = 0         
if A > 0:
    if own["oldMove"] == "A":
        own["speed"] += .02
    else:
        own["speed"] = 0
        own["oldMove"] = "A"
    own.alignAxisToVect(own.getVectTo(pointer)[1], 1, 0.15)
    own.applyMovement((-own["speed"],0,0), True)
    own["timer"] = 0 
if S > 0:
    if own["oldMove"] == "S":
        own["speed"] += .02
    else:
        own["speed"] = 0
        own["oldMove"] = "S"
    own.alignAxisToVect(own.getVectTo(pointer)[1], 1, 0.15)
    own.applyMovement((0,-own["speed"],0), True)
    own["timer"] = 0 
if D > 0:
    if own["oldMove"] == "D":
        own["speed"] += .02
    else:
        own["speed"] = 0
        own["oldMove"] = "D"
    own.alignAxisToVect(own.getVectTo(pointer)[1], 1, 0.15)
    own.applyMovement((own["speed"],0,0), True)
    own["timer"] = 0            
    
if own["timer"] >= 7:
    cont.activate(emptyrot)
    emptyrot.dRot = [0, 0, move/20] 
else:
    cont.deactivate(emptyrot)        
    
if mouseMove.positive:
    own["timer"] = 0