Início
》》》》》》》1
Tutorials LightWave 3D How to unroll a roll of parchment Qua Jan 26, 2011 2:27 am
Admin
Admin
| by Elmar Moelzer |
 |
| A few months ago, this question concerned quite a few people on NewTek's discussion- groups. Back then quite a few users tried to find an automated technique, but somehow it did not really work out. I found a rather straight forward but good and rather quick solution, or should I say a few solutions, depending on whether one wants to use 3rd- party- plugins or texturing with image- maps is required. This tutorial requires solid knowledge of LightWave®s tools and may therefore not be suitable for beginners. It requires LightWave® 6.5+. 1. The slowest solution, with UV- map and without the use of a 3rd- party- plugin: First create a long, slim Box in Modeler using these settings:  On this box we will use the tool called Sea Shell (ships with LightWave®). Please pay attention to having the checkmark "Make UVs" on! Use the following settings:  This is the result of the operation. One can clearly see the UV- map in the UV- window:  Because of the parchment being very thin, we will only need one side- wall of the spiral. One can easily select it in the UV- window (see image below).  You may delete all other polygons now (Select invert, then delete). You have to select the lower points afterwards and Stretch them down, because of the Seashell- tool offering no option for that unfortunately.  Now copy and paste the selected points into a new Layer. I decided to leave the roll of parchment in the background to be better able to follow its shape:  Select one point after the other by starting from the outermost point, following the spiral inward.  Hit [control + p] to create an open curve.  Use Make Skelegons to create Skelegons from the curve. Place a copy of them on the lower edge of the parchment.  Back into our first Layer one should open Surface Editor and make the surface of the parchment- Double- Sided. Then go into Subpatch- mode [tab]. Now our roll of parchment is not that faceted anymore. Unfortunately its outer corners happen to become rounded because of that too.  BandSaw will help us changing that quickly, first the outer edge...  ...then the inner.  Now you just have to cut and paste the Skelegons from Layer 2 back into the first Layer. Then rotate the object into a position similar to the one in the image below and the modeling- part is finished.  Now save the object and switch to... Layout First we will go to the Object- Properties and change the Subdivision- Order to "Last"  Next we will Convert the Skelegons into Bones:  The nice result of our preparations in Modeler is that all Bones now have an angle of exactly 45 degrees to each other. By setting the pitch angle of all bones (one after the other) to 0 degrees, one can easily unroll the parchment. For the other way round just reset them to 45 degrees. Now go and select the second Bone in the row and create a Motion Key on frame 1. To make things easier, do this for the "Current Item and Descendants"  Repeat this for Bone 2 on frame 2 , Bone 3 on frame 3 etc...  ...until nearly all Bones of one side have been rotated to 0 degrees.  Back at Keyframe 1, repeat this again for the Bones on the opposite side. This may seem to be more tedious than it actually is, as you just have to set all bones to 0 degrees. In fact it should not take you longer than 2 minutes.  What is really elegant about this solution is that one can easily decide to set a few Bones to slightly changed angles, which makes the unrolled parchment look much more natural and not perfectly flat:  Here is the final result, because of the UV- Map one can easily texture the parchment with an imagemap now. Alternative ways: 3rd- Party- Plugins with UV- Map: Here I use the free Helix- RT- plugin, that one can easily find on flay.com or rendering.de. By using the following settings one can easily get a similar result to the one we had in the first part of this tutorial:  Now select all points of the Spline (one after the other), beginning with the outermost.  And use "Extender"  Now move the still selected points up to make the length of the roll:  Select this polygon and delete it:  Note: depending on how many Points you have it may be faster to build another Box and use Rail Extrude Select these two polygons and use UV- Spider   The rest of this tutorial is the same as in solution 1, but with the difference that we already have the Splines for the creation of the Skelegons and therefore don't have to create them by hand. Solution 3: 3rd- Party- Plugin, very fast: Use the Helix- RT- plugin again, but this time simply extrude a copy of the resulting curve downward and then create the Skelegons from the original curve. Use UV- Spider again to create the UV- map. This is certainly the fastest solution, but be aware that it will not deform as well as a subpatch- object. It will look more like an old parchment, that starts to break at some parts. Still looking good though. Solution 4: Like solution 3, but using the Sketch- tool instead of Helix RT. This will not produce a perfectly round roll and therefore no 45- degree- angles for the Bones. It is very fast though. Final words: The UV- map you will get from all these Solutions is not perfect. All Polygons have the same length, which is wrong. I have had good (but unexpected) results from using Polygon normal UVs (a standard LightWave®- tool) and afterwards UV- Copy, Clear Map, UV- Paste (in this order) and some additional tweaking... As this is more hack than a technique (which also does nor work all the time, which seems to depend on the geometry) I wont go in depth here, though... BTW, using UV- copy, Clear Map and UV- paste will also help you getting back your control- points. These will often miss when LightWave® automatically creates the UV- maps (i.e. by using Texture Guide). I hope you enjoyed this tutorial. For questions regarding this tutorial or LightWave® in general, don't hesitate to contact me. Good luck, happy rendering and god bless! Elmar Moelzer Download the Source Files Here |
