CompuServe Thread

Hidden Line Removal

15 messages in this thread
#128168From: Carl FinchOct 10, 1994 3:05 PM
I would like to be able to print a clean-looking image of a 3ds mesh, with hidden lines removed. I've tried the 3ds.mli material called "FACEMAP HIDN LIN," but it looks weird on long objects. The long edges appear sharp, but the short edges are wide and shaded–no surprise considering the facemap technique. This is a fence-building project, so all the elements are rectangular solids (8 foot 2×4's, etc.). I've also tried wire frame, with each board composed of a wire frame "exterior" (to provide edge definition) and a slightly smaller, white interior (to hide all edges behind). But the wire frame "wires" seem to taper away at their junctions. Why should that be? I'm sure AutoCAD could do this for me, but I don't have it. Any suggestions?
#128252From: Jonas Ruikis [ADESK]Oct 10, 1994 11:15 PM
Hi Carl, << I would like to be able to print a clean-looking image of a 3ds mesh, with hidden lines removed. >> If you like any of your views of a mesh in 3ds you can always do a screen dump to a file and crop what you need. See the hidden parameter file R3HIDN.txt in the 3ds section of the lib for details.
#129105From: Carl FinchOct 14, 1994 8:32 PM
>> you can always do a screen dump to a file and crop what you need. << Thanks for replying, Jonas. I'm familiar with Screen-Grab. But unless I'm overlooking the obvious, screen-grabbing doesn't really help me at all. None of the editor display options remove hidden lines. My wooden fence models are composed of great numbers of rectangular solids–even with Backface displayed they look a mess in the editor.
#129107From: Jonas Ruikis [ADESK]Oct 14, 1994 8:44 PM
Hi Carl, << None of the editor display options remove hidden lines. >> What about from the Keyframer's Display/Geometry/Backface?
#129406From: Carl FinchOct 17, 1994 10:53 AM
>> What about from the Keyframer's Display/Geometry/Backface? << Huh? Doesn't seem to on my system! Maybe I'm not making clear what I want. I'd like to create a rendering that looks like a simple line drawing of the model–black lines on white paper, with only visible edges showing.
#129502From: Yost GroupOct 17, 1994 8:01 PM
I've been away on vacation, so I haven't been following this thread. Has anyone suggested applying a material like the FACEMAP HIDN LIN that comes with 3ds? For a really clean hidden-line effect, you might want to use a much higher resolution map than the Hidden1.cel and use different colors, but a face map material might give you what you want. – Jack
#129504From: Don LandisOct 17, 1994 8:26 PM
Render to wireframe only and render it to at least 1024×768 ar1.0. Save the file and then import it to any windows program for printing. I use render to TIF and then print the file with my HPIII using page Maker 5. This makes a nice intermediate for client approvals. Oh yes, you can assign a black material and render against a white background.
#129933From: Carl FinchOct 19, 1994 2:05 PM
>> Render to wireframe only… << Thanks for your suggestions, Don. I'm having better results by using them. In addition, I have inserted into each object a 99.75% scaled clone, assigned a white matte material. This 'fills' the original object (making it opaque) and properly blocks out objects located behind it. This works very well for my current wood fence design project (of course it doubles the mesh size). And for more complex shapes, simply scaling down and cloning an object may cause it to protrude through the original (and hide the wire framing in that area), but a bit of vertex pulling can tuck it back in.
#130043From: Michael D'AngeloOct 19, 1994 10:38 PM
Assign a wireframe material to the objects in the scene, and then render it out!
#130252From: Carl FinchOct 20, 1994 4:55 PM
I've tried this, but it only creates a "backface" sort of line removal–not complete hidden line removal. So I also create an opaque clone inside each object (and slightly smaller) which does the trick. Thanks for your help!
#129343From: Forcade & AssociatesOct 16, 1994 11:52 PM
Robert, Don't forget the extra memory overhead of loading that flic into RAM. That could put you over the edge into Swapland (not a nice place to visit). Terry Gilbert F^C mb. If it looks good, who cares what's the "kosher" thing to do? <g> Pennello applies its effects by creating "brushes" based on the underlining image and alpha masks with all sorts of forms (tiny gray scale bitmaps with different shapes and textures). These brushes "collect" image data and "paint" with it. It's sort of like having a [painter's] palette full of colors and Control-C Intercepted Menu 1 Continue 2 Return to menu/prompt 3 Return to forum top 4 Exit this forum 5 Log off Enter choice: 2
#129705From: Carl FinchOct 18, 1994 2:35 PM
>> …Modify/Edge/Autoedge… (Was that confusing enough? <g>) << No, quite clear, thanks. Unhappily, it doesn't help in this particular case because my mesh is composed of about 200 rectangular solids (Create/Box), and some of these overlap and others are arranged in an open lattice-work (these meshes are board fences). With Autoedge at 90 degrees _every_ edge disappears, and at 89 degrees _none_ do! <G> But I'll file away your suggestions for more organic shapes in the future. I don't have ACAD, but do have DesignCAD 3-D which can print/plot with hidden lines removed. Unfortunately it chokes on 3DS's DXF files–I'll have to look into why. Perhaps in the last two and a half years Amer. Small Bus. has issued an update! Your reply has confirmed my notion that there's no direct way to do it in 3ds, and that's helpful! Thanks again, John!
#129910From: Forcade & AssociatesOct 19, 1994 12:28 PM
>> >> …Modify/Edge/Autoedge… (Was that confusing enough? >> <g>) << >> No, quite clear, thanks. Unhappily, it doesn't help in this >> particular case because my mesh is composed of about 200 >> rectangular solids (Create/Box), and some of these overlap >> and others are arranged in an open lattice-work (these meshes >> are board fences). With Autoedge at 90 degrees _every_ edge >> disappears, and at 89 degrees _none_ do! <G> >> But I'll file away your suggestions for more organic shapes >> in the future. I don't have ACAD, but do have DesignCAD 3-D >> which can print/plot with hidden lines removed. >> Unfortunately it chokes on 3DS's DXF files–I'll have to look >> into why. Perhaps in the last two and a half years Amer. >> Small Bus. has issued an update! >> Your reply has confirmed my notion that there's no direct way >> to do it in 3ds, and that's helpful! Thanks again, John! DesignCAD probably expects Acadr10 DXF files which use 3Dfaces for surfaces. 3DS outputs r11/r12 DXF files that use Polyface meshes. I hope ASB has an update for you. Terry Gilbert Forcade & Associates
#130089From: Carl FinchOct 20, 1994 2:20 AM
>> DesignCAD probably expects Acadr10 DXF files… 3DS outputs r11/r12… << Ahah! Thanks for the tip, Terry. It's nice to 'know something' when approaching them; I haven't had much luck with them in the past. I bought DC3 as my initial foray into 3d animation (create a sequence of pcx snapshots in DC3, then assemble 'em with Animator's NUMPIC). ASB's documentation makes me reeeeeally appreciate Jack's 3DS docs!
#130192From: Forcade & AssociatesOct 20, 1994 12:57 PM
>>Ahah! Thanks for the tip, Terry. It's nice to 'know something' when approaching them; I haven't had much luck with them in the past. I bought DC3 as my initial foray into 3d animation (create a sequence of pcx snapshots in DC3, then assemble 'em with Animator's NUMPIC). ASB's documentation makes me reeeeeally appreciate Jack's 3DS docs! << We get a lot of software through here that we write articals about. Most of the documentation makes me appreciate Jack's 3DS docs! Terry Gilbert Forcade & Associates