Hi I'm creating a cleaning game but encountered a problem when I fast draw a straight line the line is broken but when I slow draw a straight line it works fine
Below is my code
private void Update()
{
if (Input.GetMouseButton(0))
{
if (Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), out RaycastHit hit))
{
Vector2 textureCoord = hit.textureCoord;
int pixelX = (int)(textureCoord.x * _templateDirtMask.width);
int pixelY = (int)(textureCoord.y * _templateDirtMask.height);
Vector2Int paintPixelPosition = new Vector2Int(pixelX, pixelY);
int paintPixelDistance = Mathf.Abs(paintPixelPosition.x - lastPaintPixelPosition.x) + Mathf.Abs(paintPixelPosition.y - lastPaintPixelPosition.y);
int maxPaintDistance = 7;
if (paintPixelDistance < maxPaintDistance)
{
return;
}
lastPaintPixelPosition = paintPixelPosition;
int pixelXOffset = pixelX - (_brush.width / 2);
int pixelYOffset = pixelY - (_brush.height / 2);
for (int x = 0; x < _brush.width; x++)
{
for (int y = 0; y < _brush.height; y++) {
Color pixelDirt = _brush.GetPixel(x, y);
Color pixelDirtMask = _templateDirtMask.GetPixel(pixelXOffset + x, pixelYOffset + y);
float removedAmount = pixelDirtMask.g - (pixelDirtMask.g * pixelDirt.g);
dirtAmount -= removedAmount;
_templateDirtMask.SetPixel(
pixelXOffset + x,
pixelYOffset + y,
new Color(0, pixelDirtMask.g * pixelDirt.g, 0)
);
}
}
_templateDirtMask.Apply();
}
}
}
Start Paint, and using the pen, try draw circles as fast as you can then look at the result:
Obviously, you didn't draw such straight lines with such clean direction change.
So, how is Paint able to cope up with such huge delta changes?
Interpolation
Some pseudo code:
on mouse down
get current mouse position
if last mouse position has been set
draw all the positions between last to current
use Bresenham algorithm for instance
save current mouse position to last mouse position
You could/should make your algo aware about pen size, with some simple math you can figure out the necessary step in evaluating points in the interpolation.
And don't use SetPixel, keep a copy of the texture pixels with GetPixels32 that you'll update and then upload it all at once using SetPixels32.
Related
My application works fine, 100% expected results with Canvas set on ScreenSpace-Overlay. I have written a function that takes an array of integers and based on its values it dynamically builds vertical bars inside a panel. I have an UI-Image as a prefab and that I instantiated multiple time, set its anchor to bottom left position and increase the x-offset from that point in increments of its width+padding. Everything works fine, check the screenshots.
I have now a fancy idea of animating the vertical bars... to have Unity Particle Effects on the top of each bar and to play it. From what I searched... you cannot get Particle Effects working on Canvas-UI unless the Canvas is set as ScreenSpace-Camera. I managed to obtain success with Particle Effects and ScreenSpace-Camera canvas... everything works... but now the same code that dynamically builds the UI doesnt work anymore... the vertical bars are set on a total new position outside the UI.
My Canvas
Working algorithm
My code:
private void ArrangeImagesOnCanvas(List<int> varArray)
{
Canvas canvas = FindObjectOfType<Canvas>();
//float h = canvas.GetComponent<RectTransform>().rect.height * canvas.GetComponent<RectTransform>().localScale.y;
//float w = canvas.GetComponent<RectTransform>().rect.width * canvas.GetComponent<RectTransform>().localScale.x;
float h = _panelImageForSortingAlgorithm.GetComponent<RectTransform>().rect.height * canvas.GetComponent<RectTransform>().localScale.y;
float w = _panelImageForSortingAlgorithm.GetComponent<RectTransform>().rect.width * canvas.GetComponent<RectTransform>().localScale.x;
float minH = 20.0f;
float maxH = h - 20;
int minList = varArray.Min();
int maxList = varArray.Max();
_imageWidth = (w - (varArray.Count * _PADDING)) / varArray.Count;
List<float> heightsList = new List<float>();
float _tempFloat = 0;
for (int i = 0; i < varArray.Count; i++)
{
_tempFloat = ScaleIntervals(varArray[i], new Vector2(minList, maxList), new Vector2(minH, maxH));
heightsList.Add(_tempFloat);
}
for(int i = 0; i<_instancesOfImages.Count;i++)
{
Destroy(_instancesOfImages[i]);
}
_instancesOfImages.Clear();
for (int i = 0; i < varArray.Count; i++)
{
GameObject instantiatedImage = Instantiate(_imageToInstance, _imageToInstance.transform.position, Quaternion.identity);
instantiatedImage.transform.SetParent(_panelImageForSortingAlgorithm.transform);
Image img = instantiatedImage.GetComponent<Image>();
img.rectTransform.anchorMin = new Vector2(0, 0);
img.rectTransform.anchorMax = new Vector2(0, 0);
img.rectTransform.pivot = new Vector2(0, 0);
img.rectTransform.position = new Vector3(i * (_imageWidth + _PADDING), 0, 0);
img.rectTransform.sizeDelta = new Vector2(_imageWidth, heightsList[i]);
_instancesOfImages.Add(instantiatedImage);
}
}
For the same code the vertical bars can be seen in this image...
Broken bars 1
if I put
float h = _panelImageForSortingAlgorithm.GetComponent<RectTransform>().rect.height;
float w = _panelImageForSortingAlgorithm.GetComponent<RectTransform>().rect.width;
then the vertical bars are like in this image.
Broken bars 2
How can I position correctly the vertical bars as in ScreenSpace-Overlay but this time to be on ScreenSpace-Camera ? Please help or give me some advices or tips...
i am making a game where i require a power meter. i am using drag and shoot method, and have LineRenderer as my trajectory. basically when u click and drag on the screen the ball moves in the direction it’s s dragged (just like bow and arrow). i want to display a power meter too but some how not able to achieved it. i have few approaches but they don’t give what i want. can you please have look and suggest what am doing wrong. thank you
{
ChangeAni();
if (onGround && ballMoveable)
{
if (Input.GetMouseButtonDown(0))
{
startPoint = cam.ScreenToWorldPoint(Input.mousePosition);
startPoint.z = 2;
}
if (Input.GetMouseButton(0))
{
currentPoint = cam.ScreenToWorldPoint(Input.mousePosition);
currentPoint.z = 2;
tl.RenderLine(startPoint, currentPoint);
force = new Vector2(Mathf.Clamp(startPoint.x - currentPoint.x, minPower.x, maxPower.x), Mathf.Clamp(startPoint.y - currentPoint.y, minPower.y, maxPower.y));
float powerDisplayX = Mathf.Clamp(startPoint.x - currentPoint.x, 0, power);
float powerDisplayY = Mathf.Clamp(startPoint.y - currentPoint.y, 0, power);
powerDisplay = powerDisplayX + powerDisplayY;
Debug.Log(powerDisplay);
//powerDisplay = force.x + force.y * power;
//if (powerDisplay < 0)
//{
// powerDisplay = -powerDisplay;
//}
}
if (Input.GetMouseButtonUp(0))
{
endPoint = cam.ScreenToWorldPoint(Input.mousePosition);
endPoint.z = 2;
//force = new Vector2(Mathf.Clamp(startPoint.x - endPoint.x, minPower.x, maxPower.x), Mathf.Clamp(startPoint.y - endPoint.y, minPower.y, maxPower.y));
rb.AddForce(force * power, ForceMode2D.Impulse);
tl.EndLine();
Debug.Log(force * power);
}
}```
I think you refer to the powerDisplay part.
Note that you are clamping both vector components individually so you might get a vector bigger than expected (with a maximum magnitude of sqrt(power^2 + power^2) = 1.41 * power ;)
.. you might rather want to use Vector2.ClampMagnitude
Returns a copy of vector with its magnitude clamped to maxLength.
like
powerDisplay = Vector2.ClampMagnitude(startPoint - currentPoint, power);
I'm working on a raycast based pathfinding system. Basically what I'm trying to do is generate points around an object/check if that object can reach those points, and check if those points can reach the target. The target is the green cylinder in the back of the photo. Here is my layer mask which basically says to ignore the player as a collider/obstacle:
layerMask = Physics.DefaultRaycastLayers & ~(1 << 3);
Here is my raycasting code:
// Check if enemy can see player without any obstructions
bool CanSeeDestination(Vector3 startingPoint, Vector3 destination)
{
if(Physics.Raycast(startingPoint, destination, 50f, layerMask))
{
Debug.DrawLine(startingPoint, destination, Color.red);
return false;
} else
{
Debug.DrawLine(startingPoint, destination, Color.green);
return true;
}
}
And finally my pathfinding function:
// Raycast based pathfinding
void Pathfind()
{
List<Vector3> surroundingPoints = new List<Vector3>();
bool foundTarget = false;
// Nested loop to build surrounding points vector array
for(var i = 1; i <= 10; i++)
{
for(var k = 1; k <= 10; k++)
{
// Offset by half of max to get negative distance
int offsetI = i - 5;
int offsetK = k - 5;
surroundingPoints.Add(new Vector3(transform.localPosition.x + offsetI, stepOverHeight.y, transform.localPosition.z + offsetK));
}
}
// Loop through array of surrounding vectors
for(var m = 0; m < surroundingPoints.Count; m++)
{
// If enemy can reach this surrounding point and this surrounding point has an unobstructed path to the target
if(CanSeeDestination(transform.localPosition, surroundingPoints[m]) && CanSeeDestination(surroundingPoints[m], player.transform.position))
{
float distanceFromEnemyToTarget = Vector3.Distance(transform.position, surroundingPoints[m]);
float distanceFromTargetToPlayer = Vector3.Distance(surroundingPoints[m], player.transform.position);
float totalDistance = distanceFromEnemyToTarget + distanceFromTargetToPlayer;
// If this total path distance is shorter than current path distance set this as target
if(totalDistance < currentPathDistance)
{
currentPathDistance = totalDistance;
target = surroundingPoints[m];
foundTarget = true;
}
}
}
if (!foundTarget)
{
target = transform.position;
}
}
For some reason the raycasts trigger on the right side of the obstacle but not the left. Also if I increase the obstacle size or collider size I can eventually block the left side. Not sure why raycasts on the left are green and still passing through the collider.
I resolved the issue. The problem was in this line:
if(Physics.Raycast(startingPoint, destination, 50f, layerMask))
I should have been using Physics.Linecast two go between two points. Raycast goes in a vector "Direction" linecast goes between two points. The correct code is:
if(Physics.Linecast(startingPoint, destination, layerMask))
//The following game has been designed as an educational resource
//for Key Stage 1 and 2 children. Children are the future of
//civil engineering, and to inspire them to get involved in the
//industry is important for innovation. However, today the
//national curriculum is very structured, and many children
//can find themselves falling behind even at the age of 7 or 8.
//It is essential that children can be supported with material
//they find difficult, and given the resources to learn in a
//fun and engaging manner.
//One of the topics that many children struggle to grasp is
//fractions. It is necessary to prevent young children feeling
//like STEM subjects are too difficult for them, so that they
//have the opportunity and confidence to explore science and
//engineering subjects as they move into secondary education and
//careers.
//This game intends to set a precedent for teaching complex
//subjects to children in a simple, but fun and interactive
//manner. It will show them that fractions can be fun, and that
//they are capable, building confidence once they return to
//the classroom.
//The game will work by challenging the user to split a group
//of balls into three buckets depending on the fraction
//displayed on the bucket.
int number_of_balls;
float bucket_1, bucket_2, bucket_3;
int bucket_1_correct, bucket_2_correct, bucket_3_correct;
PVector basket_position, basket_dimensions;
Ball[] array_of_balls;
int linethickness;
//Random generator to give number of balls, ensuring that
//they can be divided into the number of buckets available.
void setup()
{
size(500,500);
linethickness = 4;
number_of_balls = int(random(1,11))*6;
println(number_of_balls);
bucket_1 = 1/6;
bucket_2 = 1/2;
bucket_3 = 1/3;
//Working out the correct answers
bucket_1_correct = number_of_balls*bucket_1;
bucket_2_correct = number_of_balls*bucket_2;
bucket_3_correct = number_of_balls*bucket_3;
println (bucket_1, bucket_2, bucket_3);
println (bucket_1_correct, bucket_2_correct, bucket_3_correct);
//Creating the basket
basket_position = new PVector(width/4, height/8);
basket_dimensions = new PVector(width/2, height/4);
//Creating the balls & placing inside basket
array_of_balls = new Ball[number_of_balls];
for (int index=0; index<number_of_balls; index++)
{
array_of_balls[index] = new Ball();
}
}
//Drawing the balls and basket outline
void draw()
{
background (125,95,225);
for (int index=0; index<number_of_balls; index++)
{
array_of_balls[index].Draw();
}
noFill();
stroke(180,0,0);
strokeWeight(linethickness);
rect(basket_position.x, basket_position.y, basket_dimensions.x, basket_dimensions.y);
}
void mouseDragged()
{
if ((mouseX >= (ball_position.x - radius)) && (mouseX <= (ball_position.x + radius)) && (mouseY >= (ball_position.y - radius)) && (mouseY <= (ball_position.y + radius)))
{
ball_position = new PVector (mouseX, mouseY);
}
}
//Ball_class
int radius;
Ball()
{
radius = 10;
ball_position = new PVector (random(basket_position.x + radius + linethickness, basket_position.x + basket_dimensions.x - radius - linethickness), random(basket_position.y + radius + linethickness, basket_position.y + basket_dimensions.y - radius - linethickness));
colour = color(random(255), random(255), random(255));
}
void Draw()
{
noStroke();
fill(colour);
ellipse(ball_position.x,ball_position.y,radius*2,radius*2);
}
}
Thanks in advance for your help! I am using Processing 2.2.1 which I know is very out of date, so struggling to find help.
I have a piece of code that has created a number of balls, and I would like to be able to 'drag and drop' these to a different location on the screen as part of an educational game. I've tried playing around with mousePressed() and mouseDragged() but no luck yet. Any advice would be appreciated!
There are a lot of ways to approach this, but one way I could suggest is doing something like this:
// "Ellipse" object
function Ellipse (x, y, width, height) {
// Each Ellipse object has their own x, y, width, height, and "selected" values
this.x = x;
this.y = y;
this.width = width;
this.height = height;
this.selected = false;
// You can call the draw function whenever you want something done with the object
this.draw = function() {
// Draw ellipse
ellipse(this.x, this.y, this.width, this.height);
// Check if mouse is touching the ellipse using math
// https://www.desmos.com/calculator/7a9u1bpfvt
var xDistance = this.x - mouseX;
var yDistance = this.y - mouseY;
// Ellipse formula: (x^2)/a + (y^2)/b = r^2
// Assuming r = 1 and y = 0:
// 0 + (x^2)/a = 1 Substitute values
// ((width / 2)^2)/a = 1 x = width / 2 when y = 0
// a = (width / 2)^2 Move numbers around
// a = (width^2) / 4 Evaluate
var a = Math.pow(this.width, 2) / 4;
// Assuming r = 1 and x = 0:
// 0 + (y^2)/b = 1 Substitute values
// ((height / 2)^2)/b = 1 y = height / 2 when x = 0
// b = (height / 2)^2 Move numbers around
// b = (height^2) / 4 Evaluate
var b = Math.pow(this.height, 2) / 4;
// x^2
var x2 = Math.pow(xDistance, 2);
// y^2
var y2 = Math.pow(yDistance, 2);
// Check if coordinate is inside ellipse and mouse is pressed
if(x2 / a + y2 / b < 1 && mouseIsPressed) {
this.selected = true;
}
// If mouse is released, deselect the ellipse
if(!mouseIsPressed) {
this.selected = false;
}
// If selected, then move the ellipse
if(this.selected) {
// Moves ellipse with mouse
this.x += mouseX - pmouseX;
this.y += mouseY - pmouseY;
}
};
}
// New Ellipse object
var test = new Ellipse(100, 100, 90, 60);
draw = function() {
background(255);
// Do everything associated with that object
test.draw();
};
The math is a bit funky, and I might not be using the right version of Processing, but hopefully you found this at least slightly helpful :)
I'm kind of confused about what language you're using. Processing is a wrapper for Java, not JavaScript. Processing.js went up to version 1.6.6 and then was succeeded by p5.js. I'm going to assume you're using p5.js.
I don't know if this is a new thing in p5.js, but for easy, but not very user-friendly click-and-drag functionality I like to use the built-in variable mouseIsPressed.
If the ellipse coordinates are stored in an array of vectors, you might do something like this:
let balls = [];
let radius = 10;
function setup() {
createCanvas(400, 400);
for (let i = 0; i < 10; i++) {
balls.push(createVector(random(width), random(height)));
}
}
function draw() {
background(220);
for (let i = 0; i < balls.length && mouseIsPressed; i++) {
if (dist(mouseX, mouseY, balls[i].x, balls[i].y) < radius) {
balls[i] = createVector(mouseX, mouseY);
i = balls.length;
}
}
for (let i = 0; i < balls.length; i++) {
ellipse(balls[i].x, balls[i].y,
2 * radius, 2 * radius
);
}
}
This is the quickest way I could think of, but there are better ways to do it (at least, there are in p5.js). You could make a Ball class which has numbers for x, y, and radius, as well as a boolean for whether it's being dragged. In that class, you could make a method mouseOn() which detects whether the cursor is within the radius (if it's not a circle, you can use two radii: sq((this.x - mouseX)/r1) + sq((this.y - mouseY)/r2) < 1).
When the mouse is pressed, you can cycle through all the balls in the array of balls, and test each of them with mouseOn(), and set their drag boolean to true. When the mouse is released, you can set all of their drag booleans to false. Here's what it looks like in the current version of p5.js:
function mousePressed() {
for (let i = 0; i < balls.length; i++) {
balls[i].drag = balls[i].mouseOn();
if (balls[i].drag) {
i = balls.length;
}
}
}
function mouseReleased() {
for (let i = 0; i < balls.length; i++) {
balls[i].drag = false;
}
}
I hope this helps.
The way your code is right now doesn't work in the current version of Processing either, but it's a pretty quick fix. I'm going to show you a way to fix that, and hopefully it'll work in the earlier version.
Here's where I think the problem is: when you use mouseDragged(), you try to change ball_position, but you don't specify which ball's position. Here's one solution, changing the mouseDragged() block and the Ball class:
void mouseDragged() {
for (int i = 0; i < array_of_balls.length; i++) {
if ((mouseX > (array_of_balls[i].ball_position.x - array_of_balls[i].radius)) &&
(mouseX < (array_of_balls[i].ball_position.x + array_of_balls[i].radius)) &&
(mouseY > (array_of_balls[i].ball_position.y - array_of_balls[i].radius)) &&
(mouseY < (array_of_balls[i].ball_position.y + array_of_balls[i].radius))
) {
array_of_balls[i].ball_position = new PVector (mouseX, mouseY);
i = array_of_balls.length;
}
}
}
//Ball_class
class Ball {
int radius;
PVector ball_position;
color colour;
Ball() {
radius = 10;
ball_position = new PVector (random(basket_position.x + radius + linethickness, basket_position.x + basket_dimensions.x - radius - linethickness), random(basket_position.y + radius + linethickness, basket_position.y + basket_dimensions.y - radius - linethickness));
colour = color(random(255), random(255), random(255));
}
void Draw() {
noStroke();
fill(colour);
ellipse(ball_position.x, ball_position.y, radius*2, radius*2);
}
}
P.S. Since you're using a language based in Java, you should probably adhere to the finnicky parts of the language:
data types are very strict in Java. Avoid assigning anything that could possibly be a float to a variable that is declared as an int. For example, in your setup() block, you say bucket_1_correct = number_of_balls*bucket_1;. This might seem like not an issue, since number_of_balls*bucket_1 is always going to be a whole number. But since the computer rounds when saving bucket_1 = 1/6, multiplying it by 6 doesn't necessarily give a whole number. In this case, you can just use round(): bucket_1_correct = round(number_of_balls*bucket_1);
Regarding data types, you should always declare your variables with their data type. It's a little hard for me to tell, but it looks to me like you never declared ball_position or colour in your Ball class, and you never opened up the class with the typical class Ball {. This might have been a copy/paste error, though.
My game has a drawing tool - a looping line renderer that is used as a marker to manipulate an area of the terrain in the shape of the line. This all happens in runtime as soon as the player stops drawing the line.
So far I have managed to raise terrain verteces that match the coordinates of the line renderer's points, but I have difficulties with raising the points that fall inside the marker's shape. Here is an image describing what I currently have:
I tried using the "Polygon Fill Algorithm" (http://alienryderflex.com/polygon_fill/), but raising the terrain vertices one line at a time is too resourceful (even when the algorithm is narrowed to a rectangle that surrounds only the marked area). Also my marker's outline points have gaps between them, meaning I need to add a radius to the line that raises the terrain, but that might leave the result sloppy.
Maybe I should discard the drawing mechanism and use a mesh with a mesh collider as the marker?
Any ideas are appreciated on how to get the terrain manipulated in the exact shape as the marker.
Current code:
I used this script to create the line - the first and the last line points have the same coordinates.
The code used to manipulate the terrain manipulation is currently triggered when clicking a GUI button:
using System;
using System.Collections;
using UnityEngine;
public class changeTerrainHeight_lineMarker : MonoBehaviour
{
public Terrain TerrainMain;
public LineRenderer line;
void OnGUI()
{
//Get the terrain heightmap width and height.
int xRes = TerrainMain.terrainData.heightmapWidth;
int yRes = TerrainMain.terrainData.heightmapHeight;
//GetHeights - gets the heightmap points of the tarrain. Store them in array
float[,] heights = TerrainMain.terrainData.GetHeights(0, 0, xRes, yRes);
if (GUI.Button(new Rect(30, 30, 200, 30), "Line points"))
{
/* Set the positions to array "positions" */
Vector3[] positions = new Vector3[line.positionCount];
line.GetPositions(positions);
/* use this height to the affected terrain verteces */
float height = 0.05f;
for (int i = 0; i < line.positionCount; i++)
{
/* Assign height data */
heights[Mathf.RoundToInt(positions[i].z), Mathf.RoundToInt(positions[i].x)] = height;
}
//SetHeights to change the terrain height.
TerrainMain.terrainData.SetHeights(0, 0, heights);
}
}
}
Got to the solution thanks to Siim's personal help, and thanks to the article: How can I determine whether a 2D Point is within a Polygon?.
The end result is visualized here:
First the code, then the explanation:
using System;
using System.Collections;
using UnityEngine;
public class changeTerrainHeight_lineMarker : MonoBehaviour
{
public Terrain TerrainMain;
public LineRenderer line;
void OnGUI()
{
//Get the terrain heightmap width and height.
int xRes = TerrainMain.terrainData.heightmapWidth;
int yRes = TerrainMain.terrainData.heightmapHeight;
//GetHeights - gets the heightmap points of the tarrain. Store them in array
float[,] heights = TerrainMain.terrainData.GetHeights(0, 0, xRes, yRes);
//Trigger line area raiser
if (GUI.Button(new Rect(30, 30, 200, 30), "Line fill"))
{
/* Set the positions to array "positions" */
Vector3[] positions = new Vector3[line.positionCount];
line.GetPositions(positions);
float height = 0.10f; // define the height of the affected verteces of the terrain
/* Find the reactangle the shape is in! The sides of the rectangle are based on the most-top, -right, -bottom and -left vertex. */
float ftop = float.NegativeInfinity;
float fright = float.NegativeInfinity;
float fbottom = Mathf.Infinity;
float fleft = Mathf.Infinity;
for (int i = 0; i < line.positionCount; i++)
{
//find the outmost points
if (ftop < positions[i].z)
{
ftop = positions[i].z;
}
if (fright < positions[i].x)
{
fright = positions[i].x;
}
if (fbottom > positions[i].z)
{
fbottom = positions[i].z;
}
if (fleft > positions[i].x)
{
fleft = positions[i].x;
}
}
int top = Mathf.RoundToInt(ftop);
int right = Mathf.RoundToInt(fright);
int bottom = Mathf.RoundToInt(fbottom);
int left = Mathf.RoundToInt(fleft);
int terrainXmax = right - left; // the rightmost edge of the terrain
int terrainZmax = top - bottom; // the topmost edge of the terrain
float[,] shapeHeights = TerrainMain.terrainData.GetHeights(left, bottom, terrainXmax, terrainZmax);
Vector2 point; //Create a point Vector2 point to match the shape
/* Loop through all points in the rectangle surrounding the shape */
for (int i = 0; i < terrainZmax; i++)
{
point.y = i + bottom; //Add off set to the element so it matches the position of the line
for (int j = 0; j < terrainXmax; j++)
{
point.x = j + left; //Add off set to the element so it matches the position of the line
if (InsidePolygon(point, bottom))
{
shapeHeights[i, j] = height; // set the height value to the terrain vertex
}
}
}
//SetHeights to change the terrain height.
TerrainMain.terrainData.SetHeightsDelayLOD(left, bottom, shapeHeights);
TerrainMain.ApplyDelayedHeightmapModification();
}
}
//Checks if the given vertex is inside the the shape.
bool InsidePolygon(Vector2 p, int terrainZmax)
{
// Assign the points that define the outline of the shape
Vector3[] positions = new Vector3[line.positionCount];
line.GetPositions(positions);
int count = 0;
Vector2 p1, p2;
int n = positions.Length;
// Find the lines that define the shape
for (int i = 0; i < n; i++)
{
p1.y = positions[i].z;// - p.y;
p1.x = positions[i].x;// - p.x;
if (i != n - 1)
{
p2.y = positions[(i + 1)].z;// - p.y;
p2.x = positions[(i + 1)].x;// - p.x;
}
else
{
p2.y = positions[0].z;// - p.y;
p2.x = positions[0].x;// - p.x;
}
// check if the given point p intersects with the lines that form the outline of the shape.
if (LinesIntersect(p1, p2, p, terrainZmax))
{
count++;
}
}
// the point is inside the shape when the number of line intersections is an odd number
if (count % 2 == 1)
{
return true;
}
else
{
return false;
}
}
// Function that checks if two lines intersect with each other
bool LinesIntersect(Vector2 A, Vector2 B, Vector2 C, int terrainZmax)
{
Vector2 D = new Vector2(C.x, terrainZmax);
Vector2 CmP = new Vector2(C.x - A.x, C.y - A.y);
Vector2 r = new Vector2(B.x - A.x, B.y - A.y);
Vector2 s = new Vector2(D.x - C.x, D.y - C.y);
float CmPxr = CmP.x * r.y - CmP.y * r.x;
float CmPxs = CmP.x * s.y - CmP.y * s.x;
float rxs = r.x * s.y - r.y * s.x;
if (CmPxr == 0f)
{
// Lines are collinear, and so intersect if they have any overlap
return ((C.x - A.x < 0f) != (C.x - B.x < 0f))
|| ((C.y - A.y < 0f) != (C.y - B.y < 0f));
}
if (rxs == 0f)
return false; // Lines are parallel.
float rxsr = 1f / rxs;
float t = CmPxs * rxsr;
float u = CmPxr * rxsr;
return (t >= 0f) && (t <= 1f) && (u >= 0f) && (u <= 1f);
}
}
The used method is filling the shape one line at a time - "The Ray Casting method". It turns out that this method starts taking more resources only if the given shape as a lot of sides. (A side of the shape is a line that connects two points in the outline of the shape.)
When I posted this question, my Line Renderer had 134 points defining the line. This also means the shape has the same number of sides that needs to pass the ray cast check.
When I narrowed down the number of points to 42, the method got fast enough, and also the shape did not lose almost any detail.
Furthermore I am planning on using some methods to make the contours smoother, so the shape can be defined with even less points.
In short, you need these steps to get to the result:
Create the outline of the shape;
Find the 4 points that mark the bounding box around the shape;
Start ray casting the box;
Check the number of how many times the ray intersects with the sides of the shape. The points with the odd number are located inside the shape:
Assign your attributes to all of the points that were found in the shape.