This Is Why Your Normal Maps Are Broken In Unreal Engine - DirectX vs OpenGL

now one question I get all the time is how can my normal map doesn't look right when I import it into unreal and I don't just get this question from my students either I've actually gotten this question in production from my senior artists that have come to the project from another rendering or game engine and the answer is always the same they're using the wrong normal map format now there are two ways that a normal map can be rendered opengl and DirectX opengl has been a popular normal map format since the Inception of normal map technology it's very easy to read with your eyes it's the wysiwyg of the two formats really what you see just makes sense cracks grout and other crevices look indented while bumps and protrusions appear to stick out when you look at an opengl normal map you immediately know what you're getting this is what your 3D modeling package likely uses and most texturing Suites support it but Unreal Engine uses the other sibling format for rendering normal Maps DirectX at first glance a DirectX normal map can just look wrong it's not instantly easy to read like opengl is it almost comes off as backwards cracks and crevices are actually sticking out while protrude are indented but alas this is the format that Unreal Engine uses all right now you know what your normal map should look like in order to render correctly but you're still asking the question of what if an asset I'm using has an opengl normal map well to solve that we need to understand what the difference between the two formats is and that difference is in the y or the up Direction in a normal map the RG and B map to the X Y and Z in opengl the lighting information in the y or the green channel is coming from One Direction while the lighting information in the y direction of a DirectX normal is coming from the inverse Direction so you can literally switch formats by just inverting the green channel in the industry we call this flipping the y or flipping the green now you can permanently alter a normal map by inverting the green chain in Photoshop and re-saving it out but you can also do this non-destructively inside of unreal on the config of a texture to change an opengl normal map to DirectX inside of unreal just open up the texture go to the details panel and search for flip green to find the flip the green Channel checkbox now unreal will treat your opengl normal as if it were DirectX so if your normal Maps just don't look right inside of Unreal Engine check your normal map format and if you have the wrong format now you know how to fix it if you're looking for more unreal authorized training check the link in the description and as always don't forget to like And subscribe I'll see you next time thank you

Channel: Digital Alchemy

Views: 11,394

Keywords: unreal engine 5, unreal engine 5 beginner tips, unreal engine 5 tutorial, unreal engine 5 beginner, unreal engine tutorial, ue5 beginner tutorial, ue5 tutorial, unreal engine 5 beginner tutorial, 3d, game, lumen, nanite, epic games, fornite, launcher, unreal engine fortnite, environment art, game industry, game career, john waynick, game art, game artist, game development, virtual production, ue4, getting started, OpenGL, DirectX, Direct X, DX12, DX11, Normal Map, Open GL, Normals

Id: Wy6H8VfK_oo

Length: 3min 29sec (209 seconds)

Published: Mon May 01 2023