Is there a way to use a bump or normal texture AND a displacement map on the same appearance?
no - you have to decide, in wich way the map will be used.
And if you decide for displacement - what should a bump/normal map do for you?
eerrr.... more realism?
You can combine the displacement map, with the normal map, using an image editor to end up with a singular displacement map that combines the effects of both... But that will certainly be a bit tedious to get the desired result.
As Rob said, use 2021 for displacement since we added a lot of improvements there.
Interesting side note, I quickly looked to see if you can use a multi-layer appearance in any way to achieve this. Which you can't exactly, since the appearance with displacement will move geometry; that the other (normal only appearance) won't actually act upon. However, you can do something kind of neat in animating displacement height in this scenario....
If you need to use displacement make sure you are using Visualize 2021. Displacement in versions before 2021 doesn't work......or doesn't work well.
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