CompuServe Thread

#Using VR with DesignCAD

14 messages in this thread
#3402From: Michael H. KatzJan 23, 1995 2:54 PM
George, In an earlier posting, you mentioned that you use DesignCad 3D. Have you had much success loading DXF files from DesignCad 3D into VR for rendering? Is the process reliable? Are there any pitfalls? Thanks, Michael Katz
#3414From: Richard LindnerJan 23, 1995 7:39 PM
Michael, Please use the user's PPN. You know, the number after the name. That is the only way that CIS has of telling who you are. Just putting the name of the person means nothing to CIS and also means that the person that should have received it doesn't get a message waiting notice and has to scan thru all the messages to find it. I've forwarded your message to George Manos. Richard Lindner Forum Staff
#3427From: George ManosJan 23, 1995 10:34 PM
Michael – For the most part, the translation from DCAD to Renderize Live is reliable, but the degree of reliability depends on the nature of the original 3D model. RL will on occasion get confused by solids with openings in them created by the SOLID SUBTRACT command (which works weirdly anyway). Also, objects which to DCAD are clearly solid are not always solids to RL. A DCAD cylinder, for example, may appear to RL as a tube. However, RL has a neat feature which lets you tell it to put ends on shapes which should have them but for some reason don't. Another thing – I always leave Layer zero empty in DCAD and start with Layer 1. RL pushes Layer 1 into Layer zero. Layer 2 goes to Layer 1, etc. Layer zero in RL does not have the same action as Layer zero in DCAD. Annoying, but not catastrophic. I've generated some very primitive objects in DCAD with which to experiment in RL (squares, cubes, empty rooms) which I would be glad to send to you if you would like to see how they look. The RL images are saved in GIF format. Could send you the original DCAD files as well so you could see how well the translation went. — gtm —
#3440From: Michael H. KatzJan 24, 1995 8:39 AM
<< I've generated some very primitive objects in DCAD with which to experiment in RL (squares, cubes, empty rooms) which I would be glad to send to you if you would like to see how they look. The RL images are saved in GIF format. Could send you the original DCAD files as well so you could see how well the translation went.>> I you could send those files, I would be much obliged. What is the best way to view the GIF files? Is Corel Photo-Paint an option? Many thanks, Michael Katz
#3720From: Joel AveryFeb 2, 1995 3:18 AM
Hey George! Tell me, does the "Render Backface" option affect the appearance of your solids at all? I know in some of the models I've done this has made a world of difference in how the objects appear. Another feature that may help [one that I've never used] is changing the "Normals" of the polygons. I believe that's the icon with the arrow piercing a plane. Maybe someone with experience could chime in here and tell how they use that feature. joel* p.s. I'm still working on my list, I'm going to ply my comrades at the office for more book selections.
#3725From: Nick Josephs [VISSOFT]Feb 2, 1995 11:11 AM
If your solid object has some polygons that are facing the inside, enabling the render backface button will make a world of difference. For example, if you have a sphere in which all the normals are reversed (facing the center of the sphere), the rendered object appears to be convace from the camera's viewpoint. This is because the polygons closest to the camera a facing away from it, so they aren't rendered: instead we're seeing the inside of the back half of the sphere. Enable Render Backface and both "sides" of a polygon are rendered: now the object appears convex becasue the polygons closest to the camera are being rendered. Render backface solves backface issues, but with a price: rendering time is a little slower, and shiny materials may show highlight "halos" on the "horizon" of the object being rendered with Render Backface enabled. Which brings me to the Normals Toolbox. This allows you to choose polygons and reverse object normals, should those normals be facing in the wrong direction. This reverses the direction in which polygons are facing. The Normals Toolbox is powerful and useful, but as you may have learned through experience in the Select Toolbox, picking polygons can require some practice. I have to refer you to Tutor 10 in the Renderize Live manual that comes with Visual Reality. Thus in short, the easy way to deal with reversed polynormals is to Render Backface; the best way is to reverse the normals of the culprit polygons. Nick Josephs Visual Software
#3752From: George ManosFeb 2, 1995 9:54 PM
Hi, Joel! Have not tried rendering backfaces of solids. Have tried it with glass with great success. Rendering normals (according to the book) produces true images. Apparently some drawing packages don't care which way surfaces are generated if they are on the side of the object away from the viewer. The back face of a sphere can be concave instead of convex. Using "normals" in RL revises the surface so it can be rendered – it corrects the path of a line "normal" to the surface, thus correcting the surface (in some magic way). How does rendering the backface of a solid improve the image? — gtm —
#3849From: Joel AveryFeb 5, 1995 1:12 PM
>> How does rendering the backface of a solid improve the image? << Its kind of funny, as a rule, I usually start off rendering all backfaces simply because UpFront .DXF files usually require it for proper rendering, otherwise I end up with bits and pieces left out of the model for no apparent reason. joel*
#3861From: George ManosFeb 5, 1995 7:23 PM
Joel – What is "UpFront?" How do its DXF files import into RL? — gtm —
#3874From: Nick Josephs [VISSOFT]Feb 6, 1995 10:42 AM
Alias Upfront is a modeling application. It is compatible with Renderize Live through the DXF file format. Nick Josephs Visual Software
#3905From: George ManosFeb 6, 1995 9:58 PM
Nick – Theoretically, so is DesignCAD. Maybe I can find some users, in addition to Joel, to query on their experience with Alias Upfront. — gtm —
#3909From: Joel AveryFeb 7, 1995 3:08 AM
George: UpFront is just modeling and, while geared toward architecture, you can't generate construction documents from it but it is a great "visualization package". I've translated hundreds of little models from UpFront to Renderize via the DXF format with no significant difficulties to report. They (SketchTech, the makers of UpFront) should be out with a new version soon. It was do in november but they were having difficulty with their animation module. Their Macintosh version is beautiful and has been a stable product for at least a year, the windows version is still playing catch-up but this upgrade should even the ground a bit. joel*
#4008From: George ManosFeb 8, 1995 9:32 PM
Joel – Are you using UpFront on MAC or on a DOS platform? — gtm —
#4019From: Joel AveryFeb 9, 1995 2:31 AM
I'm using the Dos version. joel*