First: There are some self-contained editing options in the SU material options, such as hue, light and shade, transparency, size and so on. You can also adjust the size, position and orientation of the material by clicking the surface to which you want to attach the material, and then right-clicking-Map-Location. This is Sue's own function.

Second, click Edit in the SU material option, and there is a button "Edit Map in External Editor" on the right side of Tone. Click to enter the JPG material picture of ACDSEE, right-click to edit, and continue to click "Open in Editor". There are various editing methods, such as hue, rotation, cropping and so on. Then when you finish the adjustment, there will be some blanks added by the system in your picture. You need to use the Crop command to re-crop the range of material pictures you need. Finally, you click Finish and exit to save the picture.

Third, first import the texture image you want to use (in the MERTIRIAL file under the SU root directory) into PS for modification (what? You said you couldn't use PS? Then you can either brush on PS or use the method 1 and 2), and then click Edit in the SU material option. There is a checkbox for using texture. You can click the "Browse" button below it to browse and select the modified texture picture.

I hope it helps you.