The DrawCircle method

[chekhyr]

Hello. At the start of your video (around 0:10) you rendered a circle using DrawCircle(Vector2.zero, 1, Colour.lightBlue). I've searched all around the Internet but were unable to find any similar method as a part of UnityEngine. Could you provide some info on the method, please? Did you write it yourself, or is it a part of some extension?

[kailando]

Hei @morniehtar, maybe it is not part of UnityEngine? I think, here is not a good place to get help with UnityEngine.

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Use GitHub Issues to track ideas, feedback, tasks, or bugs for work on GitHub.

[CubaKay]

I think it's a asset called shapes (in the assets store)

[Mustenaka]

@CubaKay i'm not sure is this? https://assetstore.unity.com/packages/tools/particles-effects/shapes-173167

[Mustenaka]

i try to impl the particle render use GPU Instance, replace the video draw code. hope could help you.

Here is the shader code(hlsl)
`
Shader "Custom/InstancedSphereShader"
{
Properties
{
_MainTex ("Base (RGB)", 2D) = "white" { }
_Color ("Color", Color) = (1,1,1,1)
_ParticleRadius ("Particle Radius", Float) = 0.1
}
SubShader
{
Tags { "RenderType" = "Opaque" }
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile_instancing
#include "UnityCG.cginc"

        struct appdata
        {
            float4 vertex : POSITION;
            float4 color : COLOR;
        };

        struct v2f
        {
            float4 pos : POSITION;
            float4 color : COLOR;
        };

        // parma Shader array
        StructuredBuffer<float4> _Positions : register(t0); 
        StructuredBuffer<float4> _Colors : register(t1);

        float _ParticleRadius;

        // Vertex shader: Passes the instance position and color to the fragment shader
        v2f vert(appdata v, uint instanceID : SV_InstanceID)
        {
            v2f o;
            o.pos = UnityObjectToClipPos(v.vertex);

            // Read the position information for each ball from an array of instances
            o.pos.xyz += _Positions[instanceID].xyz;
            o.color = _Colors[instanceID];

            return o;
        }

        half4 frag(v2f i) : SV_Target
        {
            return i.color;  // return the color of the particle
        }

        ENDCG
    }
}
FallBack "Diffuse"

}
`
Create a material use this shader
On MonoBehavior, should define this:

`
public Material instancedMaterial; // GPU INSTANCE MATERIAL
private Vector3[] _velocitys;
private Vector3[] _positions;

private Matrix4x4[] _instanceTransforms;
private Color[] _instanceColors;
`

On Start function, init all.

then Use this to render:

`
private void OnDrawGizmos()
{
// Draw Particles
if (_positions != null)
{
Gizmos.color = Color.white;
foreach (var position in _positions)
{
Gizmos.DrawSphere(position, ParticleRadius);
}
}

        // Draw bounding box
        Gizmos.color = Color.green;
        Gizmos.DrawWireCube(Vector3.zero, BoundsSize);
    }

`

I am also following this video to implement the SPH algorithm and apply it to my project, I hope this will be helpful to you