RayTracingAccelerationStructure.CullInstances

Заполняет RayTracingAccelerationStructure экземплярами трассировки лучей, которые Unity связывает с рендерерами в Scene с помощью параметров фильтрации и отбора.

Предыдущее содержание структуры ускорения может быть факультативно очищено с помощью RayTracingAccelerationStructure.ClearInstances. После вызова этой функции, дополнительные экземпляры трассирования лучей могут быть добавлены в структуру ускорения с помощью RayTracingAccelerationStructure.AddInstance функции.

Если RayTracingInstanceCullingConfig.instanceTests если массив пуст, то эта функция не имеет никакого эффекта.

Построить ускорительную структуру на GPU, звонок RayTracingAccelerationStructure.Build или CommandBuffer.BuildRayTracingAccelerationStructure.

Дополнительные ресурсы: RayTracingShader.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;

// This script can be attached to a Camera.
public class CullInstancesExample : MonoBehaviour
{
    // A RayTracingShader is defined in a .raytrace file.
    public RayTracingShader rayTracingShader = null;

    public bool enableRayTracedReflections = true;
    public bool enableRayTracedShadows = true;

    private int cameraWidth = 0;
    private int cameraHeight = 0;

    private RenderTexture rayTracingOutput = null;
    private RayTracingAccelerationStructure rayTracingAccelStruct = null;

    void Start()
    {
        if (SystemInfo.supportsRayTracingShaders == false)
        {
            Debug.Log("The system doesn't support Ray Tracing.");
            return;
        }

        RayTracingAccelerationStructure.Settings accelStructSetting = new RayTracingAccelerationStructure.Settings(RayTracingAccelerationStructure.ManagementMode.Manual, RayTracingAccelerationStructure.RayTracingModeMask.Everything, -1);
        rayTracingAccelStruct = new RayTracingAccelerationStructure(accelStructSetting);
    }

    void OnDisable()
    {
        if (rayTracingAccelStruct != null)
        {
            rayTracingAccelStruct.Release();
            rayTracingAccelStruct = null;
        }

        if (rayTracingOutput)
        {
            rayTracingOutput.Release();
            rayTracingOutput = null;
        }

        cameraWidth = 0;
        cameraHeight = 0;
    }

    void OnRenderImage(RenderTexture src, RenderTexture dest)
    {
        if (SystemInfo.supportsRayTracingShaders == false || rayTracingShader == null)
            return;

        if (cameraWidth != Camera.main.pixelWidth || cameraHeight != Camera.main.pixelHeight)
        {
            if (rayTracingOutput)
                rayTracingOutput.Release();

            rayTracingOutput = new RenderTexture(Camera.main.pixelWidth, Camera.main.pixelHeight, 0, RenderTextureFormat.ARGBHalf);
            rayTracingOutput.enableRandomWrite = true;
            rayTracingOutput.Create();

            cameraWidth = Camera.main.pixelWidth;
            cameraHeight = Camera.main.pixelHeight;
        }

        RayTracingInstanceCullingConfig cullingConfig = new RayTracingInstanceCullingConfig();

        cullingConfig.flags = RayTracingInstanceCullingFlags.EnableLODCulling | RayTracingInstanceCullingFlags.EnableSphereCulling | RayTracingInstanceCullingFlags.EnableSolidAngleCulling;

        // Configure LOD culling.
        cullingConfig.lodParameters.fieldOfView = Camera.main.fieldOfView;
        cullingConfig.lodParameters.cameraPosition = Camera.main.transform.position;
        cullingConfig.lodParameters.cameraPixelHeight = Camera.main.pixelHeight;
        cullingConfig.lodParameters.orthoSize = 0;
        cullingConfig.lodParameters.isOrthographic = false;

        // Configure sphere culling. Accept only objects for which the enclosing AABBs are inside (or intersect) a sphere with a radius of 100 units around the camera.
        cullingConfig.sphereCenter = Camera.main.transform.position;
        cullingConfig.sphereRadius = 100.0f;

        // Configure solid-angle culling. Accept only objects for which the projected solid angle with the apex in cullingConfig.lodParameters.cameraPosition is larger than 5 degrees.
        cullingConfig.minSolidAngle = 5.0f;

        // Disable anyhit shaders for opaque geometries for best ray tracing performance.
        cullingConfig.subMeshFlagsConfig.opaqueMaterials = RayTracingSubMeshFlags.Enabled | RayTracingSubMeshFlags.ClosestHitOnly;

        // Disable transparent geometries.
        cullingConfig.subMeshFlagsConfig.transparentMaterials = RayTracingSubMeshFlags.Disabled;

        // Enable anyhit shaders for alpha-tested / cutout geometries.
        cullingConfig.subMeshFlagsConfig.alphaTestedMaterials = RayTracingSubMeshFlags.Enabled;

        // Configure which triangles are double sided. For best ray tracing performance, triangle culling should be disabled.
        cullingConfig.triangleCullingConfig.checkDoubleSidedGIMaterial = true;
        cullingConfig.triangleCullingConfig.frontTriangleCounterClockwise = false;
        cullingConfig.triangleCullingConfig.optionalDoubleSidedShaderKeywords = new string[1];
        cullingConfig.triangleCullingConfig.optionalDoubleSidedShaderKeywords[0] = "_DOUBLESIDED_ON";
        cullingConfig.triangleCullingConfig.forceDoubleSided = false;

        // Configure Material types. Render queue intervals can also be used here.
        cullingConfig.alphaTestedMaterialConfig.optionalShaderKeywords = new string[1];
        cullingConfig.alphaTestedMaterialConfig.optionalShaderKeywords[0] = "_ALPHATEST_ON";

        cullingConfig.transparentMaterialConfig.optionalShaderKeywords = new string[1];
        cullingConfig.transparentMaterialConfig.optionalShaderKeywords[0] = "_SURFACE_TYPE_TRANSPARENT";

        // Configure a Material test. Allow only Shaders that have a mandatory Shader Tag.
        cullingConfig.materialTest.requiredShaderTags = new RayTracingInstanceCullingShaderTagConfig[1];
        cullingConfig.materialTest.requiredShaderTags[0].tagId = new ShaderTagId("RenderPipeline");
        cullingConfig.materialTest.requiredShaderTags[0].tagValueId = new ShaderTagId("MyAwesomeRP");

        List<RayTracingInstanceCullingTest> instanceTests = new List<RayTracingInstanceCullingTest>();

        // Configure instance tests. There can be one instance test for each ray tracing effect for example.
        // The purpose of instance tests is to use different settings (layer, material types) per ray tracing effect.
        // Use InstanceInclusionMask argument of TraceRay HLSL function to mask different instance types.

        if (enableRayTracedReflections)
        {
            RayTracingInstanceCullingTest instanceTest = new RayTracingInstanceCullingTest();
            instanceTest.allowTransparentMaterials = false;
            instanceTest.allowOpaqueMaterials = true;
            instanceTest.allowAlphaTestedMaterials = true;
            instanceTest.layerMask = -1;
            instanceTest.shadowCastingModeMask = (1 << (int)ShadowCastingMode.Off) | (1 << (int)ShadowCastingMode.On) | (1 << (int)ShadowCastingMode.TwoSided);
            instanceTest.instanceMask = 1 << 0;

            instanceTests.Add(instanceTest);
        }

        if (enableRayTracedShadows)
        {
            RayTracingInstanceCullingTest instanceTest = new RayTracingInstanceCullingTest();
            instanceTest.allowTransparentMaterials = false;
            instanceTest.allowOpaqueMaterials = true;
            instanceTest.allowAlphaTestedMaterials = true;
            instanceTest.layerMask = -1;
            instanceTest.shadowCastingModeMask = (1 << (int)ShadowCastingMode.On) | (1 << (int)ShadowCastingMode.TwoSided);
            instanceTest.instanceMask = 1 << 1;

            instanceTests.Add(instanceTest);
        }

        cullingConfig.instanceTests = instanceTests.ToArray();

        rayTracingAccelStruct.ClearInstances();
        rayTracingAccelStruct.CullInstances(ref cullingConfig);

        // Additional ray tracing instances can be added manually using RayTracingAccelerationStructure.AddInstance function.
        // rayTracingAccelStruct.AddInstance(...);

        rayTracingAccelStruct.Build(Camera.main.transform.position);

        // Use Shader Pass "Test" in surface (material) shaders.
        rayTracingShader.SetShaderPass("Test");

        rayTracingShader.SetAccelerationStructure("g_AccelStruct", rayTracingAccelStruct);
        rayTracingShader.SetTexture("g_Output", rayTracingOutput);

        rayTracingShader.Dispatch("MainRayGenShader", rayTracingOutput.width, rayTracingOutput.height, 1);

        Graphics.Blit(rayTracingOutput, dest);
    }
}

Это пример того, как создать, заполнить и построить структуру ускорения. Содержание структуры ускорения определяется путем настройки параметров выделения и фильтрации, которые передаются функции CullInstances.