When I create some 3D objects in Photoshop CS6 (a good example would be one of a dinner-plate), artefacts always show on the surface of the plate.

A screen capture would be easier to visualize than your written words. Here is one I created

Shading artifacts point to "bad" geometry like non-convex polygons, overlapping edges and all that. as JJ Mack said, a screenshot would tell a lot along with proper system info, since hardware acceleration issues may also figure in here.

Mylenium

Those type of artifacts point to reversed normals and/or overlapping triangles. And a seam is visible on the left (either overlapping faces and/or normal issues).

(the normal is the perpendicular to the surface of the object that the light hits - if it is reversed it results in "inverted" calculations)

These can be fixed by exporting the object (right-mouse click on the 3d object layer, and choose "Export 3D layer" to an *.obj file, and repairing the issues in a 3d application such as Blender (which is free and open source).

How to fix normals in Blender:

https://www.youtube.com/watch?v=192ek4E8eYk

Where did you get that object, by the way?

Photoshop's 3D functionality is rather awkward and pales in comparison to "proper" 3d applications. There is a whole new exciting world awaiting you if you have never dabbled in 3d before.

To learn more about Blender (and 3d in general) visit http://cgcookie.com/blender

The Basics course is completely free (as is Blender). And of course it is available for Mac. Download it here: blender.org - Free and Open 3D Creation Software

And as for Christmas baubles:

Made in Blender :-)

Follow the tutorial here: Christmas bauble

Herbert2001 wrote:

 

Photoshop's 3D functionality is rather awkward and pales in comparison to "proper" 3d applications. There is a whole new exciting world awaiting you if you have never dabbled in 3d before.

 

To learn more about Blender (and 3d in general) visit http://cgcookie.com/blender

The Basics course is completely free (as is Blender). And of course it is available for Mac. Download it here: blender.org - Free and Open 3D Creation Software

 

And as for Christmas baubles:

Made in Blender :-)

Follow the tutorial here: Christmas bauble

Is everything in the above graphic CGI?  Pretty impressive if it is, right down to the limited depth of field, and the texture and shading on the ribbon. I've always struggled to get to grips with Photoshop 3D, and find it much easier with After Effects. Can you think back to when you started using Blender, and how easier it was to get into?

I started with 3D in my teens (Amiga Sculpt/Animate 4D 1987) - from a personal perspective I "grew up" with 3d applications.

I have taught Blender (and other 3d application) classes, though, and like any other software it depends a bit on the person. If you have never used a 3d application before, then Blender is relatively easy to pick up. The basic tutorials on Blender Cookie (and many other sites) are easy to follow. Learning 3D is fun, and can also be intimidating at times, because there is so much to learn in terms of scope.

My advice is to pick your battles: the above image is not that hard to recreate in Blender (together with that tutorial) once you understood the basic GUI and handling of Blender.

The funny thing is that when 3D was introduced in Photoshop, I kept thinking and wondering why the developers made it so unintuitive and hard to use. It is quite slow and cumbersome - compared to Cinema 4D, Blender, Max, Lightwave, and so on, Photoshop's 3d always kills me. I just do not want to deal with it - and the quality is well below par compared with the current state of rendering technology. I am not saying it is useless (far from it), just that once you become aware of what is out there, and are dazzled by what even free software such as Blender can pull off, it sort-of becomes a "frog leaves the well" paradigm shift.

Point in case: the above image is completely CG and done in Blender. And if you have a decent Nvidia GPU you can even render on the GPU (many times faster). In the above tutorial the instructor looks around the scene while it is rendering in almost real-time - thanks to Blender's GPU renderer. Change a material, and see it update in almost real-time. Splendid! Compare that to Photoshop's archaic and dead-slow renderer, and you will never want to go back.

Here are the demo reels for 2014 and 2013 to get a basic idea of what Blender is capable of nowadays. It's insane to think this is freely available to anyone! And if you like After Effects: Blender has smoke and fluid sims, as well as a nodal compositor with full 3d scene and object tracking. Passes can be sent to After Effects and Photoshop for further editing.

Starting in your teen would be a great starting place one's mind is as spunge at thirteen however the technology was not ready for me in 1953.   3D looks like a lot of work and not somthing I want to start at my age.   However if I were too I would definitely start with a program designed to be a 3D program from the ground  up.   Took a quick look at blender it has so many pallets and controls it made Photoshop look like a toy.  I quietly close it and never looked deep into it nor di I want too. I'm retired and am enjoying that life.   Even with Google Sketch up I was able to draw a crude model of my home, create a video  and output jpegs. Sketchup is a toy without the other application created along with it but is easy to use. http://www.mouseprints.net/old/dpr/House.mp4

So on my Google earth my house is 3D....

Any 3d application is overwhelming at the beginning - and Blender's interface is somewhat different, since it runs on all operating systems, and does not rely that much on the OS's standard GUI elements. When you have time, walk yourself through the basic tutorials, and it will make much more sense. Remember the first time you opened Photoshop or Illustrator? Every journey starts with but a single step :-)

As for normal fixing, there is a simple workflow. FIrst, download Accutrans:

http://www.micromouse.ca/downloads.html

Accutrans is a much simpler application meant for 3d object conversions and quick fixes (such as normal issues).

Then follow the simple tutorial I made for you here:

http://estructor.altervista.org/normalfix/normal%20fix.htm

If this does not fix all your problems, you probably have overlapping faces. That can only be resolved in a 3d application, unfortunately. Or try simplifying your curve in Photoshop.

True, Google SketchUp is the easiest 3d creator currently available - it's fun to dabble with, and the objects can be imported into Photoshop as well.