CompuServe Thread

#bend objects

18 messages in this thread
#117031From: Chuck RogersAug 8, 1994 1:54 PM
Systop. Question. I have made a grided object that I want to bend into several morphable objects, like a piece of paper turning a page on a book;(Schreiber Instruments) makes a routine called "Imagine page" that I am tring to copy by hand. Anyway when I m make the object, tessellate the faces, and then bend the faces, i find that the faces do not bend in a desired way. They elongate and forshorten in un realistic ways. Is there a way to bend an object, like a piece of paper, so that it looks real and not distorted without going to the IPAS routine? My second question. I would like to aquire the Special Effects Creation Toolkit aka. 3D Studio Plug-In Toolkit. How and where do I aquire it, and How Much? Last quetion. With this toolkit, is there help through the forum, and also a users group?
#117116From: MARTIN G FOSTERAug 8, 1994 7:49 PM
Charles, >> Is there a way to bend an object, like a piece of paper, so that it looks real and not distorted without going to the IPAS routine? << create a mesh with mesh.pxp – it will ask you how many grids you want and what size. You will now have an object with suitable face orientation and it should be bendable quite nicely.
#117131From: Chuck RogersAug 8, 1994 9:43 PM
Martin There isn't a mesh.pxp but there is a grid.pxp which is what I am refering to I made an object with grid, like a piece of paper, 11x 8-1/2 and gave it a thickness (1/64), no problem with that part. Then I put 3 holes in it just like the real thing. By the way I made the grid 11 x 9 x 1 to make it simple. This is where I dispute what you say about the object looks natural. I went into the editor, and selected some of the faces and not the object. The reason for this is to lift one corner, for example, first, then lift more of it, etc. until I ge enough morphs to do the job. What happens, the faces become elongated and become longer than they should be. The holes stretch out of porportion. It does not look as it should. What I am leading to is this. If you where to take a piece of string with lets say 10 steps, and do a bend on it, will it be the same length or would it stretch to something else? Also You didn't answer my other questions on the Toolkit, on line help for it, and a users group for these IPAS programs. Thanks Chuck
#117155From: MARTIN G FOSTERAug 9, 1994 12:22 AM
Chuck, >> There isn't a mesh.pxp but there is a grid.pxp << my mistake, sorry. That's what I meant. This is getting a bit too complicated to analyze effectively on the forum. All I can do (without trying it myself) is try and understand the problem and give hints. If the bend is not perfectly along the length or width of the paper then this problem is a little more complex. You'd need to anticipate the direction of the bend and then construct geometry with the edges aligned perpendicular to that. Possibly a grid with a lot more complexity might do it. Either that or tesselating and orienting faces manually with the modify/edge/divide and modify/edge/turn commands. >> If you where to take a piece of string with lets say 10 steps, and do a bend on it, will it be the same length or would it stretch to something else? << It should be. There's no scaling going on. >> Also You didn't answer my other questions on the Toolkit, on line help for it, and a users group for these IPAS programs. << That's simply because I don't have answers about those questions. You might have luck asking that again in the IPAS usage or Developers sections. Martin
#117369From: Chuck RogersAug 9, 1994 11:35 PM
Martin Tesselating and orienting faces manually with the modify/edge/devide and modify/edge/turn commands on a grid object. >> I did the first part (tesselate) and then did the bend. I do understand the concept, will try. Thanks. Chuck:)
#117739From: Jeffrey HeftAug 11, 1994 9:39 AM
FWIW, when I have wanted a bend without the distortion problems inherent in the bend routine I use rotate instead. Once I have the face edges aligned to best advantage (perpendicular to direction of bend) I create a box aligned as in Ara's message. This allows me to easily align the user view perpendicular to the bend line by using User View/Align/Face (this may not be necessary if the object is already aligned to Front, Top, or right/left view). Then I select sets of vertices, realign the Axis to the edge of the "bend" using Axis/Align/Place, and then Modify/Vertices/Rotate the selected set. Repeat as necessary. Slower, but it might get you what you want. Hope this helps. JDH
#117170From: ARA GREGORIANAug 9, 1994 7:43 AM
here is an other way to do it: 1- make your mesh using grids.pxp 2- make a cube smaller than the grid size. 3- orient the cube over the grid at the proper angle at which you want the paper to bend(you should endup with to concentric square shapes at relitive rotation angle to one another as vewied from top). hope this made sence?! 4- make sure the cube also intersects the grid as viewed from side. 5- make a bullion subtraction of grid from cube. 6- get rid of all sides of the resulting object except the grid side. 7- vouala… you have a new flat grid with diagonal lines that can be bent at a diagonal. It is much simmpler than it sounds, try it. Best is to buy the page roll and curl pxp from Schriber let me know how it worked. ara
#117196From: Don LandisAug 9, 1994 9:33 AM
Good trick, but how do you bend more than 180 degrees? as in rolling it up. I used topas for this until the Schreiber IPAS.
#117290From: ARA GREGORIANAug 9, 1994 3:49 PM
Now i dont think that you can do without distorting the mesh. i have never done what you need (bending more than 180), but here is an other sugestion. i am not sure if it will work! 1-start with 2d shaper and draw a straight line with a lot of segments. 2- copy this line several times (equal to number of morphs you need) 3- edit each line by moving and rotating each segment to show differant positions of the curling paper as you would see a pagr curl from the side. 4- outline all edited lines. 5-go to lofter and loft each outline in 2 d shaper to the same straight length. calling each lofted shape curl1, curl2….. 6- now in key framer you have a bunch of shapes that can be morphed. 7- if it does not work buy page curl from schriber <G>. take care ara
#117371From: Chuck RogersAug 9, 1994 11:48 PM
Ara I like the concept of making all the lines in the shaper and then lofting them, but when the paper turns, it should have an angle to it lets say in the "Z" axis. Also, 3D Studio should be able to do this function with out the extra expence, no? Chuck
#117410From: John TissavaryAug 10, 1994 1:49 AM
PMJI, Chalres, but part of the beauty of 3DS is that it is an open program. There are so many important things that people think "should" be part of 3DS. Personally, I could live without page turning for the rest of my life. I would like to see things like IK, NURBS or other advanced spline modeling capabilities, real-time shaded previews/views, programmable/custom shader rendering interface, etc… Who's to say what special little features get included in 3DS? That's what Plug Ins are for. John Tissavary (LUNA cie, inc)
#117504From: Chuck RogersAug 10, 1994 11:40 AM
John. Your right about that about that! The point I was making was that a program like this should have the capabilities to bend an object without disstortion as an integral function and not an add on, third party program. Wouldn't you agree? Chuck <Reel Images>
#117614From: John TissavaryAug 10, 1994 7:48 PM
I completely agree, and I think this capability should come from the modeler and what types of objects the keyframer can manipulate. I would like to see a good spline modeler (we'll see a patch modeler in R4) and the ability to keyframe animate solid objects using deformation tools like skeletons and lattices. I think stuff like this will be possible via Plug-ins coming this fall. The real strength of 3DS is that its shortcomings can be eliminated with add-ons. John Tissavary (LUNA cie, inc)
#117420From: ARA GREGORIANAug 10, 1994 2:04 AM
Then, if you can get away with less than 180 bend, my message #117170 to you which i sent yesterday should do the job! Let me know what you think about that trick. ara
#117562From: Don LandisAug 10, 1994 4:12 PM
Oh, that does work, I've done it but it is a real bear to do and also coordinate with the rest of the scene. I found it easier (and faster rendering) to do in Topas. The same project took me over 50 morph objects when I gave up in 3DS. Page curl is today's answer to the problem. Well worth the cost for the IPAS unless you work for free. One thing is very nice about 3DS and that is the IPAS concept. It has enabled me to build quite a varied collection of goodies to do just about anything. Python is another IPAS that has many uses to save time. I'm looking forward to the IK and metaballs too. Now if I can ever get that refraction working without having to fake it I'll almost be completly outfitted.
#117665From: ARA GREGORIANAug 10, 1994 11:40 PM
refractions… give it a few more months. i am sure it will be there in form of an ipas. plus we will have so much more the it will make our heads spin!!! ipas is a major "kick_ss". ara
#117230From: Brian Rudolph [Adesk]Aug 9, 1994 11:15 AM
<<My second question. I would like to aquire the Special Effects Creation Toolkit aka. 3D Studio Plug-In Toolkit. How and where do I aquire it, and How Much? Last quetion. With this toolkit, is there help through the forum, and also a users group?>> IPAS toolkit cost $250. You will also need a compiler and Phar Lap linker. Call 800-964-6432, or talk to your Autodesk dealer. More detailed questons about Developing applications should be posted in the Software Dev, Kits section (10). There are many users groups, but I don't know which ones will have people knowledgeable in programming. However, the best user group around is this forum. -Brian
#117372From: Chuck RogersAug 9, 1994 11:51 PM
Brian Thanks Chuck