Unity HybridRender 使用Unity.Rendering.FrustumPlanes 结构体来实现视锥体裁剪。这个结构体基本都为静态函数,其中使用NativeArray<PlanePacket4>作为参数的函数是HybridRenderSystem中进行裁剪的函数。从试验结果看,如果需要在逻辑层判断是否在视锥体内,可以考虑使用FromCamera(Camera camera, NativeArray<float4> planes)构造视锥体6个平面,然后使用Intersect(NativeArray<float4> cullingPlanes, AABB a)这个函数获取判断结果。判断结果是个enum:Out,In, Partial。
using FrustumPlanes = Unity.Rendering.FrustumPlanes;
public class FrustumCut : SystemBase
{
Camera mainCam = null;
string camTag = "MainCamera";
protected override void OnCreate()
{
base.OnCreate();
mainCam = FindCamera(camTag);
}
[BurstCompile]
protected override void OnUpdate()
{
if (mainCam == null)
{
mainCam = FindCamera(camTag);
return;
}
var plans = new NativeArray<float4>(6, Allocator.TempJob);
FrustumPlanes.FromCamera(mainCam, plans);
Dependency = Entities
.ForEach((Entity e, int entityInQueryIndex,in WorldRenderBounds bounds ) =>
{
var r = FrustumPlanes.Intersect(plans, bounds.Value);
//DO ANYTHING HERE...
}).Schedule(Dependency);
plans.Dispose(Dependency);
}
Camera FindCamera(string tag)
{
var go = GameObject.FindGameObjectWithTag(tag);
if (go == null)
return null;
return go.GetComponent<Camera>();
}
}
}