12:54 AM, Friday November 4th 2022
Here is what I did to help see cast shadows in textures.
Randomly folded piece of paper, flattened and then illuminated with a light from one side at a 45 degree angle. I snapped a photo, made it monochrome and boosted the contrast. Since the paper itself is white, any level of grey is a shadow. The darker the shadow, the 'deeper' the contour.
https://i.imgur.com/jzY2TRR.jpg
Here is a crumple piece of paper prepared the same way.
https://i.imgur.com/22A1TmD.jpg
This helped me to see the cast shadows as they relate to texture more clearly. I hope you find it helpful.