I am having trouble with UVs. Currently Vectorworks>Datasmith>UE5 gives UVs that look a mess when viewed with the UE5 UV Editor. (I only import geometery no textures.)
I’ve watched tutorials for the past week but still struggle to use the UV editor to get satisfactory UV maps. Part of this could be because I come primarily from the CAD world and I’m not sure I completely understand the relation of UVs and material instances when it comes to sizing.
I’ve experimented with every setting in the UV editor and other than turning islands to their proper orientation I find it difficult to use the tools to manipulate the UV maps into a sensible order.
Some of the things I am tyring to get a grip on…
texel size and its relation to texture size/tiling
UV islands coming in 90 degrees off compared to some that are texturing properly
UV islands with different heights/widths even though they share a common edge in the model
I don’t know if Vectorworks is generatiing the UV maps or some automated process UE5. Either way maybe are they so messed up that I can’t use the UV editor to fix them.
Can I get where I need to go using the built in UV editor to manipulate the UV map or do I need to explore passing through Blender or Maya to manipulate the UVs?
I’m struglging and have more questions but this post is long enough already. If anyone can point me in the right direction I’d appreciate it.
I’ve had some, but not extensive, experience with CAD-sourced models and textures.
In general, the CAD program textures are “materials,” and thus don’t have inherent directionality. Thus, even if the UVs overlap, that’s fine, as long as they have the right scale for the material I’m using in-engine. When the scale is off, I can either correct in the shader, or I can scale the UV charts in the Engine editor. Which I go with, depends on specifics.
When using baked lighting, you will also need a non-overlapping set of UVs that is used for light maps. This is best generated by the engine, as a second set of UV coordinates. There’s an option to do this in the mesh editor, the only thing to watch out for is to set the right texture coordinate channel index in the properties so you don’t overwrite the material texture coordinates.
In this case I am only importing geometry via Datasmith but it still comes in with ugly UV maps.
You are correct in that the over lapping UVs mostly work except some of them are turned 90 degrees and thus the applied texture too. Weeding through the stacked UV’s to adjust them is tedious with the editor but it may be a similar time suck whether I do it in the editor or use another program to make these adjustments.
There are no UVs generated for lighting in this case so letting the engine create them in another channel is spot on.
The CAD program we are using is well suited for everything but UE so I’m stuck with it. I’m just going to keep working via trial an error to find the best path for getting good UVs for UE.
Why does orientation matter? “stucco” or “beige paint” or “aluminum profile” typically don’t have an orientation. Although some things, like carpet, or wood paneling, might have some orientation that matters, yet not warrant modeling at the detail level like, say, roof tiles would.
Also, presumably, the CAD models render with some kind of texture coordinate in the CAD program – how do those texture get the orientation “right,” if it matters? Can you do the same thing in your material?
Finally, it’s possible to process the data. You could look at the geometry you get in, and look at the UV orientation, and if you detect a vertical surface, where the U/V direction is not what you want it to be, you could rotate the coordinates automatically as part of the pipeline. Doesn’t work for carpets, though. (Also remember to rotate your tangent basis to match, or re-compute it, after UV rotation!)
I was only importing geometry because I didn’t like the CAD textures and planned to replace them with Megascan textures anyway. When I added the Megascan texures after importing only geometry it looked like the image attached above.
So I tried importing with geometry, textures and materials then applied Megascan textures in place of the CAD textures, adjusted rotation, and everything worked!
Much like crafting The perfect bowl of Miso Soup with clam requires a skilled chef, delving into the realm of UV Soup and UV Editor demands precision and expertise. UV Soup and UV Editor play pivotal roles in the field of computer graphics, particularly in 3D modeling. Just as the flavors in miso soup need careful balance, these tools allow artists to manipulate textures and unwrap 3D models with finesse, ensuring a visually appealing outcome. So, just as a chef refines the blend of miso and clam in a soup, digital artists skillfully use UV Soup and UV Editor for a seamless and visually delightful creation process.
