So I made a roblox gfx and it has denoising, but I made a new one, and it doesnt. I have no idea why- and the difference is very clear. You can also see that the second one is kinda transparent. And they are both cycles Also, I have blender 2.90.1 so its like... Thanks!!
You have set your render engine to EEVEE rather than Cycles. EEVEE doesn't have denoising. If you switch back to Cycles then the render pass for denoising, as well the render options for render time denoising will reappear:
Note that if you did switch from Cycles to EEVEE you may have to modify your compositor nodes when you switch back.
$\begingroup$ awhhh thank you so much for your answer!! it is very appreciated although, they are both cycles. :( $\endgroup$– MikiaSep 13, 2021 at 3:33