How To Draw A Staight Line In Id

The unity line renderer, helps y'all render lines, circles, and other shapes using curves. As well equally some coordinate points in unity and then that you can create any sort of curves. Yous tin depict color lines in 2d to help you with raycasts or merely draw light amplification by stimulated emission of radiation beams betwixt ii points or objects.

This will be rendered on run fourth dimension using a line renderer component in unity. Line renderers are useful for drawing paths in your games.

For instance a application of line renderers are in the famous game Angry Birds.

Where a path is drawn by dragging on a mobile screen.

Line renderer can also help in targetting systems where y'all want to draw a raycast of where a bullet might shoot to in a first person game.

The unity line renderer component can also exist used in building basic drawing apps using the unity engine.

All these applications make line renderers a actually of import thing to learn in unity.

In this tutorial I volition be going over a few principles. Drawing a unity line renderer between a mouse / screen tap, dragging it and cartoon it on your scene.

We will also look at drawing a line renderer between 2 game objects.

Dotted lines is likewise something people are quite interested in and I volition wait at how nosotros can depict a unity 2d line renderer which can give us a dotted line.

Let'due south get started on this unity 2d line renderer tutorial, and so to showtime I'm going to create a bones unity projection which nosotros can experiment with.

Creating our unity second line renderer project

Showtime off by opening unity hub. Create a new 2d project called unity second line renderer. Like below:

With a new blank project. Nosotros desire to outset by just setting upwardly some basic game objects. And then that we can but become to the office of only drawing a basic line renderer.

Create a empty game object. Right click in the hierarchy and create a empty game object like beneath.

Next create a new c# script and phone call it unity line renderer test. Similar below.

Creating a bones unity add line renderer by script using c#

Let u.s. a construct a bones line renderer script.

                      LineRenderer l = gameObject.AddComponent<LineRenderer>();                  List<Vector3> pos = new List<Vector3>();         pos.Add together(new Vector3(0, 0));         pos.Add(new Vector3(x, ten));         l.startWidth = 1f;         l.endWidth = 1f;         l.SetPositions(pos.ToArray());         l.useWorldSpace = truthful;        

This code volition produce a line like this.

Let's now try do something a little more complicated. Let's create a triangle with the renderer.

To do this nosotros need the start width to be 0 and the terminate width to be a larger number. Besides let's change our positions.

LineRenderer 50 = gameObject.AddComponent();

                      Listing<Vector3> pos = new List<Vector3>();     pos.Add(new Vector3(0, v));     pos.Add(new Vector3(0, -10));     l.startWidth = 0f;     l.endWidth = 15f;     l.SetPositions(pos.ToArray());     l.useWorldSpace = true;        

And then let's just walk through this lawmaking quick. So we create two positions nosotros too create commencement and end widths.

Where the indicate which makes the summit of the triangle being a width of only 0 and the bottom portion being 15.

Let's brand a foursquare line renderer.

This should be similar to the triangle shape. Except nosotros will make our 0 width xv to match the bottom. So here is the code.

                      LineRenderer fifty = gameObject.AddComponent<LineRenderer>();                  List<Vector3> pos = new List<Vector3>();         pos.Add together(new Vector3(0, 5));         pos.Add(new Vector3(0, -10));         50.startWidth = 15f;         l.endWidth = 15f;         l.SetPositions(pos.ToArray());         l.useWorldSpace = true;        

Let'due south now look at how we can do something somewhat more advanced let us try create a circle. For this we going to employ a few basic mathematics functions to use pi and depict points.

                      for (int i = 0; i < pointcounter; i++)         {             var radian = Mathf.Deg2Rad * (i * 360f / segments);             points[i] = new Vector3(Mathf.Sin(radian) * radius, Mathf.Cos(radian) * radius,0);         }        

And then as yous tin run across you lot tin can create a whole lot of different shapes using a line renderer. This tin give you a lot of freedom to generate these shapes on the fly at run fourth dimension in your games.

Allow us now look at how we tin color our line renderer.

Unity line renderer color changes

For demonstrating color in our renderer nosotros volition get back to using a our square shape.

Allow'southward create one solid colour for our line to do that add these 2 lines to your code.

                      fifty.startColor = Color.ruddy;   l.endColor = Colour.scarlet;        

You demand to then hit run on your projection. You will get this pinkish for now. I will show you how to fix it.

To gear up this you need to head over to the right while running your project.

Click on that little circle icon and assign a material.

You should now have this where you colour is correct.

Let's create a gradient for our line renderer.

Change your code to have these colors.

                      l.startColor = Color.red;     l.endColor = Color.white;        

Follow the same steps from earlier and y'all should now go a square that looks like this.

This is now all good and well if nosotros only need two colors. Let'south look at using a multiple colour gradient.

Change your code to use this instead.

          Gradient g = new Gradient();          float alpha = ane.0f;          yard.SetKeys(             new GradientColorKey[] { new GradientColorKey(Color.green, 0.0f), new GradientColorKey(Colour.cherry, 0.5f), new GradientColorKey(Colour.blue, 1.0f) },             new GradientAlphaKey[] { new GradientAlphaKey(alpha,0.0f), new GradientAlphaKey(alpha, 0.5f), new GradientAlphaKey(alpha, 1.0f) }         );         l.colorGradient = g;        

Then how this lawmaking works is nosotros first define a new gradient object. We accept a alpha of 1.0 so nosotros accept full opacity. So we need to add gradient color keys for each color we want in our gradient.

So our gradient primal has two values, one is the color the other is a time value.

The fourth dimension value determines how far our slope will stretch hither are two examples of what the above lawmaking would look like vs the same code with different fourth dimension values.

The lawmaking that produces the above is this gradient colour keys.

          new GradientColorKey(Color.green, 0.0f), new GradientColorKey(Color.ruby-red, 0.2f), new GradientColorKey(Color.blueish, 1.0f)        

So as y'all can run into the change to 0.2f on the cherry calibration makes our greenish function of our gradient shorter, because our green is from 0 to 0.2f.

I remember we have at present covered a lot on gradients with line renderers and ways to colour your line renderer.

Besides if you wanted to adjust transparency of your line renderer you lot would be able to do it by changing that alpha value.

Permit's at present look how we tin describe a line renderer between two game objects.

Unity line renderer between 2 gameobjects

For this section of the tutorial we want to go and create ii cubes. We will and so create a line renderer which will draw betwixt these two game objects. So go ahead in your project and right click in your hierarchy and create 2 cubes.

One time done click on this 2d button to switch into 3d view.

So movement your cubes then they are somewhat apart in your scene similar the below screenshot.

Let us too add a directional light so that our scene is more than lit up.

You lot should now have something like this.

Finally to get our photographic camera into 3d view we need to click on our main camera and modify this settings.

To make your photographic camera align to your view you demand to click on align to view in the carte like this.

So if you hit play on your scene you will now end upwards with your two cubes in your scene in 3d perspective view.

Let united states of america now change our code so we tin can describe betwixt two game objects.

          using System.Collections; using System.Collections.Generic; using UnityEngine;  public class UnityLineRendererTest : MonoBehaviour {     // First is called before the first frame update     public GameObject go1;     public GameObject go2;     void Start()     {         LineRenderer l = gameObject.AddComponent<LineRenderer>();          Listing<Vector3> pos = new Listing<Vector3>();         pos.Add(go1.transform.position);         pos.Add(go2.transform.position);         50.startWidth = 0.1f;         l.endWidth = 0.1f;         l.SetPositions(pos.ToArray());         fifty.useWorldSpace = true;       }     }                  

In one case you have updated your code to this. Go ahead and drag your two cubes into the game object slots like this.

You should now end up with something like this.

Allow's movement our code into our update method now so we can see how nosotros can morph our line renderer past moving our cubes around the scene. So update your lawmaking to this.

          using System.Collections; using Organization.Collections.Generic; using UnityEngine;  public class UnityLineRendererTest : MonoBehaviour {     // Start is called before the outset frame update     public GameObject go1;     public GameObject go2;     LineRenderer l;     void Start()     {         l = gameObject.AddComponent<LineRenderer>();      }        // Update is chosen one time per frame     void Update()     {         List<Vector3> pos = new List<Vector3>();         pos.Add together(go1.transform.position);         pos.Add(go2.transform.position);         l.startWidth = 0.1f;         l.endWidth = 0.1f;         l.SetPositions(pos.ToArray());         l.useWorldSpace = true;     } }                  

Yous should now be able to do this when yous run your project.

That pretty much sums upward how you tin draw a line renderer between ii objects in unity equally well as move information technology effectually and change information technology.

Unity line renderer performance

Allow's talk almost performance. Line renderers generally doesn't have a very high operation cost, but make sure to not over use them.

Too when using them brand sure to have a proficient clean up strategy or pooling or re use strategy and then that you don't keep creating new renderers.

Using best practices for cleaning upwards objects is always advise in unity. So brand sure to write sound lawmaking which will aid yous clean upwardly later yourself.

We have now done some line renderers betwixt 2 points, between two gameobjects, nosotros have looked at different shapes and line renderer coloring.

Let's look at something a little more advanced. Permit us effort and render a curve.

Oft asked questions

What is line renderer in unity?

A line renderer in unity is a object which allows you to draw lines. Using multiple points, then with a line renderer you can draw any type of object if you provide enough points to construct information technology. Line renderers are useful for trails for aiming.

How do you draw a line in unity?

You more often than not would use a line renderer to draw any lines in unity.

How do yous make a laser in unity?

Depending on how basic you lot desire to go, you tin use a line renderer to draw your lazer beam across the co ordinates of your ray cast. If you desire something more effect rich you may want to use a particle upshot.

Last words

Cheers for following this tutorial on line rendering in unity 2d and 3d. If yous liked this tutorial please share it on social media and consider subscribing to my youtube aqueduct here: https://www.youtube.com/channel/UC1i4hf14VYxV14h6MsPX0Yw

I have as well a bunch of other tutorials on game evolution in general. Then experience gratis to check out some of those tutorials and articles from this listing.

Source: https://generalistprogrammer.com/unity/unity-line-renderer-tutorial/

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