[hdrp] Memory Leak In 2019.2.0a9 (and 0a11)

Since upgrading to 2019.2 alpha, I have had some errors occurring and a bunch of garbage collection warnings repeatedly.

Errors:

Recursive rendering is not supported in SRP (are you calling Camera.Render from within a render pipeline?).

Assertion failed on expression: '!GetPersistentManager().IsStreamLoaded(metaDataPath)'

Asset import did not unload metadata path. This will leak memory. File a bug with repro steps please. (Assets/Prefabs/Parts/Hands/Cannons/Gauss Cannon.prefab)

GUI Window tried to begin rendering while something else had not finished rendering! Either you have a recursive OnGUI rendering, or the previous OnGUI did not clean up properly.

Assertion failed on expression: 'device.IsInsideFrame()'

Warnings (many, repeatedly, even with nothing in scene):

GarbageCollector disposing of ComputeBuffer allocated in C:\Unity\Host 3D - 2019.2 alpha\Library\PackageCache\com.unity.render-pipelines.high-definition@6.6.1-preview\Runtime\Lighting\LightLoop\LightLoop.cs at line 846. Please use ComputeBuffer.Release() or .Dispose() to manually release the buffer.

UnityEngine.ComputeBuffer:Finalize()

GarbageCollector disposing of ComputeBuffer allocated in C:\Unity\Host 3D - 2019.2 alpha\Library\PackageCache\com.unity.render-pipelines.high-definition@6.6.1-preview\Runtime\RenderPipeline\HDRenderPipeline.cs at line 366. Please use ComputeBuffer.Release() or .Dispose() to manually release the buffer.

UnityEngine.ComputeBuffer:Finalize()

GarbageCollector disposing of ComputeBuffer allocated in C:\Unity\Host 3D - 2019.2 alpha\Library\PackageCache\com.unity.render-pipelines.high-definition@6.6.1-preview\Runtime\Lighting\VolumetricLighting\VolumetricLighting.cs at line 251. Please use ComputeBuffer.Release() or .Dispose() to manually release the buffer.

UnityEngine.ComputeBuffer:Finalize()

GarbageCollector disposing of ComputeBuffer allocated in C:\Unity\Host 3D - 2019.2 alpha\Library\PackageCache\com.unity.render-pipelines.high-definition@6.6.1-preview\Runtime\Lighting\Shadow\HDShadowManager.cs at line 219. Please use ComputeBuffer.Release() or .Dispose() to manually release the buffer.

UnityEngine.ComputeBuffer:Finalize()

I don't know if the erroneous metadatapath prefabs (often containing new VFX effects) are connected to the hdrp garbage collector issues.

I'm sure I have missed out something useful for helping to get to the bottom of this so please suggest anything I can do to help debug this!

My project is becoming unworkable at the moment, the play/stop functions take 10x longer than usual, and this gets progressively worse over each session.

Thanks in advance!

[Packages]

Code (CSharp):

1. {
2.   "registry": "https://staging-packages.unity.com",
3.   "dependencies": {
4.     "com.unity.2d.sprite": "1.0.0",
5.     "com.unity.2d.tilemap": "1.0.0",
6.     "com.unity.ads": "2.3.1",
7.     "com.unity.analytics": "3.3.2",
8.     "com.unity.collab-proxy": "1.2.16",
9.     "com.unity.package-manager-ui": "2.2.0",
10.     "com.unity.probuilder": "4.0.4",
11.     "com.unity.purchasing": "2.0.6",
12.     "com.unity.render-pipelines.high-definition": "6.6.1-preview",
13.     "com.unity.textmeshpro": "2.0.0",
14.     "com.unity.timeline": "1.0.0",
15.     "com.unity.visualeffectgraph": "6.6.1-preview",
16.     "com.unity.xr.legacyinputhelpers": "2.0.2",
17.     "com.unity.modules.ai": "1.0.0",
18.     "com.unity.modules.androidjni": "1.0.0",
19.     "com.unity.modules.animation": "1.0.0",
20.     "com.unity.modules.assetbundle": "1.0.0",
21.     "com.unity.modules.audio": "1.0.0",
22.     "com.unity.modules.cloth": "1.0.0",
23.     "com.unity.modules.director": "1.0.0",
24.     "com.unity.modules.imageconversion": "1.0.0",
25.     "com.unity.modules.imgui": "1.0.0",
26.     "com.unity.modules.jsonserialize": "1.0.0",
27.     "com.unity.modules.particlesystem": "1.0.0",
28.     "com.unity.modules.physics": "1.0.0",
29.     "com.unity.modules.physics2d": "1.0.0",
30.     "com.unity.modules.screencapture": "1.0.0",
31.     "com.unity.modules.terrain": "1.0.0",
32.     "com.unity.modules.terrainphysics": "1.0.0",
33.     "com.unity.modules.tilemap": "1.0.0",
34.     "com.unity.modules.ui": "1.0.0",
35.     "com.unity.modules.uielements": "1.0.0",
36.     "com.unity.modules.umbra": "1.0.0",
37.     "com.unity.modules.unityanalytics": "1.0.0",
38.     "com.unity.modules.unitywebrequest": "1.0.0",
39.     "com.unity.modules.unitywebrequestassetbundle": "1.0.0",
40.     "com.unity.modules.unitywebrequestaudio": "1.0.0",
41.     "com.unity.modules.unitywebrequesttexture": "1.0.0",
42.     "com.unity.modules.unitywebrequestwww": "1.0.0",
43.     "com.unity.modules.vehicles": "1.0.0",
44.     "com.unity.modules.video": "1.0.0",
45.     "com.unity.modules.vr": "1.0.0",
46.     "com.unity.modules.wind": "1.0.0",
47.     "com.unity.modules.xr": "1.0.0"
48.   }
49. }

 

I have same errors. Some random prefabs (old and new) write errors like:

Asset import did not unload metadata path. This will leak memory. File a bug with repro steps please. (Assets/_Project/Resources/Prefabs/Effects/Bonfire.prefab)

Started with hdrp 6.6 and 2019.2.09, eat lot of memory in some scenes - 8 , 12 gb ram and then just crash.

 

I'm sorry, I've been trying to whittle down the factors that cause this but it seems to occur sometimes, and sometimes not, with hugely variability. I can't create a simple project/scene that causes the error reliably.

The only common thing I can find with the prefabs that exhibit this error is their VFX effects. Aside from this, they're just .fbx models with no texture, a simple "Metal" custom HDRP material, and some small behaviour Mono's.