To recreate this error, draw 2 simple shapes in Illustrator CS6, copy and paste them together as a Shape layer in Photoshop CS6.
Then go to 3D > New 3D Extrusion from Selected Path. I just accept the defaults.
Then go to 3D > Split Extrusion.
The error is thrown at this point. No matter what I do, I can't get it to work.
I've tried rasterizing the shape, but then I get a different error. When I select 3D > New 3D Extrusion from Selected Layer, I get the error: "Could not complete the New 3D Extruions from Selected Layer command because the path is too complex." This is ridiculous. I can't get the 3D to work at all.
Is Photoshop just this buggy or am I trying to do something that should not be possible? If so, the error message certainly should be more helpful than what I'm seeing.
I can't duplicate any of what you say at all. Multiple paths are always extruded as a single entity, so there is actually nothing to split and you should get a different warning. That is, if your paths are clean and logical. Anyway, we cannot know. You are not offering any info about your system nor what exactly you do in AI to produce ther paths, how your clipboard is set and so on. Lots of details. Could even be that you use the 64bit version of AI or something like that and it has a bug that screws your paths while it might work perfectly in the 32bit version...
You may have answered my question. I AM using the 64bit version of Illustrator CS6. I had no idea there were bugs in it that affected paths copied and pasted from Illustrator to Photoshop.
A bit more about what I'm trying to accomplish... I'm trying to follow Deke's tutorial (http://www.deke.com/content/dekes-techniques-018-creating-a-3d-pie-cha rt) which is already difficult since so much has changed between CS5.5 and 6, but then on top of that, I keep getting errors!
So I created the pie chart exactly as he shows and copied and pasted into Photoshop exactly as he does. Before submitting this post, though, I tried drawing just two very simple triangle shapes, copying them both and pasting them into Photoshop as a shape layer. The shapes weren't overlapping, but they were a part of the same shape layer just like the pie chart tutorial.
Thanks for your help. If there is anything else I should try before just giving up because of the 64bit bugs, please let me know.