Create a simple Wireframe render for your 3d asset

1.  To begin with, save your scene as something else.  Call it "Wireframe_Render".  If something breaks, you can always go back.

2.  Select everything in your scene, Right-click > Convert to Editable Poly.

3.  Start by attaching all of your pieces together so that you have only 1 mesh.  You can do this easily by selecting any piece of your object and using the Attach function.

4.  Once everything is attached, create a new flat gray-shaded material and apply it to your object.  Give it a little specularity if you want for flavor.  To do this, open the material browser (hotkey M) and with your object selected, click the Assign Material to Selection button.

5.  Make a copy of your object and name it Wireframe_Object or something that you can remember.  To quickly copy your object, press Control + V with your object selected.

 6.  With your Wireframe_Object still selected, apply a Lattice modifier to it and adjust some of the parameters.  See the screenshot below for my settings.  (The Radius amount will differ depending on the size of your object. If the Lattice wireframe is too big and can't seem to get any smaller, rescale your prop up super big, Reset XForm, then try again.)

7.  Apply a simple black material to your Lattice object, pose and render your image!  (Hotkey to render is F9)

Hope that helps!