I would really appreciate any help. New to blender. I am trying to make a 3d model in blender then export as obj to take into Adobe Dimension. I have been trying for days and everything I make that I render in Dimension is black. My guess is the UV on my models. Pre made items like the monkey or far left tube with the top taken off work. but not the 2 center things i made using the circle mesh. Also I noticed the inside of the far left tube is always rendered black on the inside. I can also import other obj from online, add sub surface to smooth and then into dimension and it is fine. Any insight into what I need to change on my model to render correctly would be amazing. Thank you.
you can see that the ones that dont work are a different blue/gray colour in the 3D viewport. This means the normals are inverted and need to be flipped (your mesh is inside out). Select the object, go into edit mode, ctrl+F, flip normals and see if that fixes the colour.