this bug is still valid:
http://fogbugz.unity3d.com/default.asp?1224369_7mrk4u7mtf10ar0u
we can’t even use the stacking option (base/overlay) because it does have other bugs too, which we will report separately.
Hey @sebas771 , uninitialized means that the load action for that specific RenderTarget will be DontCare instead of Load or Clear. This is something that should be used as an optimization when you know that you are going to overwrite all the pixels, otherwise the behaviour is “undefined”.
The reason why the results in most cases will look different between editor and player, is that the Editor doesn’t run on TBDR GPUs, so DontCare load actions are effectively no-ops, but on TBDR GPUs you will have uninitialized tile memory and the contents are not defined.
A quick explanation of the expected undefined behaviour when using “uninitialized” taken from the Vulkan spec:
VK_ATTACHMENT_LOAD_OP_DONT_CARE specifies that the previous contents within the area need not be preserved; the contents of the attachment will be undefined inside the render area. For attachments with a depth/stencil format, this uses the access type
So in case you want to use the results of a previous frame as RT for the next one you need to implement an ad hoc solution where you store the results you want to preserve in a separate RT and then write to it in the next pass/frame
I hope this explains your issue?
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OK I may have misunderstood the original report. In our case, I am talking about 2 cameras, not using RT programmatically.
so the equivalent of the old don’t clear option doesn’t exist in URP?
if you are using camera stacking “Don’t clear” (so basically “Load” load action) is the default behaviour of overlay cameras, it will load cameraColor and cameraDepth (unless you use the ClearDepth option) from the previous camera
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I am reporting the issue on behalf of my colleague so I may miss something, but Don’t Clear doesn’t exist on an URP camera:
for the Overlay Camera, yes it worked, but we had other issues, that I will report separately in case.
By the way @ManueleB what do you think about this other report? Various problems with URP and upscaling in 2021.3
I think this is actually the only real bug we think we encountered
If you intended usage is to keep the results of a previous frame and reuse them in the following frame then you are correct, “Don’t Clear” is not possible.
As I mentioned in the first post, a possible way to implement that in URP would be writing a custom pass/render feature that stores the result of the previous frame in a “persistent” RT and then read from that in the next frame
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I’ll forward this internally so someone can have a look, thanks!
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thank you!
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