Changing Texture Scale doesn't impact UV values.

[ebarMLN7G]

We export our Revit models using IExportContext API. We have had some issues with inaccurate UV values that we get through PolymeshTopology.GetUV method. It seems like the UVs don't accurately reflect the texture scale. We did a few tests and changed the scale of the texture, and it seems like that doesn't really have any effect on the UV values that we are getting. What are we missing?

[RPTHOMAS108 · Accepted solution]

UV Values are probably related to how face is constructed not texture mapping. So you'll likely have to convert from your sample size units to how the UV's are measured in the model for a particular type of face (given the known internal units used).

https://forums.autodesk.com/t5/revit-api-forum/revit-api-iexportcontext-converting-uv-to-the-range-0...

https://thebuildingcoder.typepad.com/blog/2020/12/dynamo-book-and-texture-bitmap-uv-coordinates.html

The problem I've found with texture mapping recently is that sample for something such as wood grain is too small so when you repeat it over a surface during render you notice the same feature such as knots repeating in a way that looks obviously artificial. Would be good if they had a number of similar samples randomly mapped so that there is less noticeable uniformity.