Not quite sure what you're asking...
First off, what version of Photoshop?
For Photoshop CC for example you could, once you have your text layer current, choose 3D - New Extrusion from Selected Layer.
Then you'll be working in the 3D environment, where you can do all sorts of things to the extruded shapes.
I'm working in PS CC. I did exactly what you replied and still no prompt in
the 3D tool bar.My computer is a I Mac 24 in.. Perhaps it needs a video
card.This is the Graphics it contains.
Chipset Model: ATI,RadeonHD2600
PCIe Lane Width: x16
VRAM (Total): 256 MB
Vendor: ATI (0x1002)
Device ID: 0x9583
Revision ID: 0x0000
ROM Revision: 113-B2250F-219
EFI Driver Version: 01.00.219
Is this enough.
Thanks Richard Valeo
Ah, now I see the issue. You need at least 512MB of video RAM to use Photoshop 3D.
Can I increase the video ram or get a new computer..
Someone else will have to advise you on iMac capabilities... I'm not familiar with the system.