I created a 3D object on photoshop using a PNG image. Once imported to Dimension using OBJ, the image and texture are not attached. I believe they are saved as separate files but how can I then add them to dimension maintaing the same image and aspect?
when you exported your Obj file from Photoshop you made a mistake... the most common error is not generating a Uv map in Photoshop before export... if this is where you went wrong the 3D file will need to be fix in Dimension, try selecting the model and add a new material... that should also generate a default Uv you can then add your texture to
but export Uv back to Photoshop is the only way to fix scale issues... again it is normally best to generate the Uv map in Photoshop before moving onto Dimension and if you still have the working out files that is what I recommend