topic Re: folded or crumpled textile in Modeling

folded or crumpled textile

Anonymous — Fri, 04 Feb 2005 00:08:42 GMT

Hello
How can I make in 3D a folded textile, and a crumpled textile ?

Thanks for your help!

Charlotte C.
student in architecture

Re: folded or crumpled textile

Anonymous — Fri, 04 Feb 2005 02:17:56 GMT

You have 3 options as I see it.

1. Use a material/fill pattern on an existing object/tool.

2. Find someone who has or will make an object that is what you need, this will probably require money.

3. Make the object yourself, if you are not good with GDL you could try playing with profiler or the mesh tool.

It really depends on what you want it for and how detailed it needs to be.

Ditto for the net in the other post.

Julia

Re: folded or crumpled textile

Anonymous — Fri, 04 Feb 2005 08:20:23 GMT

Thanks for your answer.

If I use an existing textile I have, what do I do with it? Do I scan it? And then? I put it on a wall as a material in archicad?

thanks again to help me

Re: folded or crumpled textile

Anonymous — Fri, 04 Feb 2005 08:37:43 GMT

PS: by "material" I mean 'texture'......

?

Re: folded or crumpled textile

Anonymous — Sun, 06 Feb 2005 04:43:44 GMT

I am probably not the best person to answer this, but I will have a go.

If you scan/ take a digital photo of your material you can take it into photoshop or similar and create a texture out of it. I expect books on photoshop, in most Uni libraries will help you if you can't get hold of Dwight's book 'Illustration in Archicad'.

The simple bit is attaching the texture to a material and placing it on a wall.

Julia

Re: folded or crumpled textile

ci-JoshOs — Sun, 06 Feb 2005 21:46:09 GMT

You could also put an alpha channel in it so that you can get some nice bump mapping action.
mmmm.... textiley

Re: folded or crumpled textile

Anonymous — Fri, 11 Feb 2005 17:07:39 GMT

You might try looking here:
http://transstudio.com/

More specifically at at product called Foldtex, but Mr. Brownell has collected a very wide assortment of materials for possible architectural use.

This is a quote from his pdf catalog

"TRANSMATERIAL
A catalog of materials, products and processes
that are redefining our physical environment."

Happy hunting

Re: folded or crumpled textile

Karl Ottenstein — Sat, 12 Feb 2005 03:30:54 GMT

charlotte wrote:
How can I make in 3D a folded textile, and a crumpled textile ?

Hi Charlotte,

You want to distinguish the shape and the appearance of the surface.

For the shape, you will likely want to use the mesh tool. If you have the Cigraph ArchiForma 2 add-on, you can easily create some other appropriate shapes.

I have some experience scanning and photographing fabrics since my wife is a weaver and I have done some machine knitting. My experience is that scanning provides unsatisfactory results because of the reflection of the scanner bulb on the fibers. Taking (digital) photographs without flash is much more satisfactory.

You will have to turn your picture into a tile-able image ... one that can repeat vertically and horizontally. As others have said, Photoshop is where to do this. Because of the nature of fabric, it is most helpful if you have a swatch that you can pin (block) onto a board so that is perfectly square, but otherwise you can remove distortion in Photoshop. (For woven fabric, the weft and warp threads must align exactly when tiled, for example.) You must photograph at least one complete repeat pattern if the textile has a repeat (whether in color or texture). This is all pretty easy once you're used to it, but might be tedious the first time.

Create a new material with the resulting image as the texture file and apply it to the mesh or other object.

Have fun,
Karl

Re: folded or crumpled textile

Aussie John — Sat, 12 Feb 2005 07:21:45 GMT

Karl wrote:
the weft and warp threads must align exactly when tiled, for example.) You must photograph at least one complete repeat pattern if the textile has a repeat (whether in color or texture). This is all pretty easy once you're used to it, but might be tedious the first time.

I must say I have never understood how you get a pattern to repeat ( and I still dont ) any advise would be greatfully received

Re: folded or crumpled textile

Karl Ottenstein — Sat, 12 Feb 2005 20:35:08 GMT

Aussie wrote:
I must say I have never understood how you get a pattern to repeat ( and I still dont ) any advise would be greatfully received

Hi John,

From your past posts, I think you do? So, maybe I don't understand the question. Maybe you are talking about textile repeats and not texture images?

The repeat of the image file is of course done automatically by ArchiCAD: whatever image is loaded for a material is repeated indefinitely vertically and horizontally. (In Piranesi and Artlantis, we have the choice to repeat in only one direction or none.)

Visible repeats are of course the bane of most materials - grass, wood, stone, etc.

Patterns in textiles are discrete - picks or stitches (think pixels) - and most conventional techniques result in a repeat. (Free-form patterns - intarsia and overknitting for knit fabric, and drawloom and tapestry techniques for woven fabric are an exception of course.) Because of this, it is easy to crop and touch up an image of a textile to make it repeat perfectly.

Cropping an image of a wallpaper pattern is similar. To make it repeat perfectly requires a uniformly lit image greater than the repeat and cropping (at pixel level zoom) to exactly where the same pixels from the left appear again on the right, and from the bottom appear at the top.

But, that's probably not what you were asking...?

Karl

Re: folded or crumpled textile

Aussie John — Sat, 12 Feb 2005 23:34:25 GMT

Sorry Karl Iwas meaning in photoshop. If you take picture I dont know how you make the image align on opposing sides so they will flow seamlessly when joined to form a texture

Re: folded or crumpled textile

Dwight — Sun, 13 Feb 2005 03:21:53 GMT

Building a seamless texture from a photo involves copying pixels for uniformity.

If you are on mac, a utility called "Texture Magic" will assoist you in copying pixels and provided a full-screen preview to show the repeat pattern.

In photoshop, you can copy pixels across image edges by using the offset - locate - see attached

Re: folded or crumpled textile

Dwight — Sun, 13 Feb 2005 03:22:33 GMT

and here it is

Re: folded or crumpled textile

Karl Ottenstein — Mon, 14 Feb 2005 19:32:13 GMT

Aussie wrote:
Sorry Karl Iwas meaning in photoshop. If you take picture I dont know how you make the image align on opposing sides so they will flow seamlessly when joined to form a texture

Figured I misunderstood! 😉

Thanks to Dwight for providing the answer. Let me add a couple of other comments since this thread was started by a student for whom these things may be new concepts.

When a "seamless" texture is repeated, you should be unable to detect where the edges of the original image lie. Even in the case of a single tile with grout repeating to show an entire surface of tile, the edges need to be managed as Dwight desribes to avoid an observable pixel line when the image is repeated.

But, a "seamless" texture does not mean that it lacks a repeating pattern - desired or undesired. An example of an undesired repeating pattern is the grass texture in the standard ArchiCAD materials which is seamless, but which has an unattractive repeat.

The wallpaper example is one where the pattern of the paper should repeat, but the edges of the base pattern should not be visible ... and so again, Dwight's technique is used to shift the pattern (offset filter) to clean up any edge pixels if required.

Back to textiles!

Fabric can be deformed, making the creation of a seamless, tile-able texture a little challenging. Camera lenses cause other issues. (A scanner eliminates the camera lens issue - but as mentioned in my earlier post, it does not give a genuine sense of the appearance of the fibers.)

Before taking a photo of a textile, is should be blocked to be as perfectly rectilinear as possible. If you manage to do this perfectly, then lens distortion is the main thing to address in making a texture.

Avoid a wide angle lens. If you use one, then use the free Panorama Tools plug-in for Photoshop to remove the lens distortion.

If the image is taken at a slight angle to the fabric / textile, then when you use offset, the rows (weft, knit, whatever) will not align since they will be denser on one side of the image and spaced further apart on the other side. Use the Photoshop Transform/Distort command along with the Photoshop Grid (ctrl-') to make the rows and columns (warp and weft) of the fabric rectilinear. Then try the Offset filter again. Repeat as necessary.

Below is a screenshot, with contrast articificially adjusted to help make the pattern show. The red grid is the Photoshop grid (you can change the color and size). The red arrows show that at the top, there is only a slight shift from the left to the right of the image, but at th bottom, there is a greater shift. The Distort command will correct this "bias"/distortion. (I just took a quick photo without blocking, and intentionally holding the camera at an angle to the surface. Bad lighting, etc. just because I'm doing this as I type.

Karl

Re: folded or crumpled textile

Karl Ottenstein — Mon, 14 Feb 2005 19:38:58 GMT

After free-transforming the image to make the rows and columns align reasonably (not perfect because there is some distortion in the fabric since I did not block it), I cropped one repeat-pattern and used the Offset command as indicated by Dwight.

This results in the image attached. The red arrows show where the "seams" are - the original edges of the cropped image before the offset.

You can see that the vertical edge matches surprisingly well and does not need much touch-up. The horizontal edge has a noticeable pixel pattern and requires some cloning after trimming another pixel row or two off.

Karl

Re: folded or crumpled textile

Dwight — Mon, 14 Feb 2005 19:56:37 GMT

Copying edge pixels often enhances another problem - illumination is not totally uniform so the repeated image "pulses" once tiled.

The user must be very careful to also copy enough pixels into the main body of the sample to disguise this problem.

Of course, experimenting with the procedural shaders of LightWorks, coupled with bitmap masks for tile edges can help overcome this problem by eliminating the need for phototextures in most cases.

And yes, that is gorpy granite. This project is, after all, art for a Haitian Bordello.

Re: folded or crumpled textile

Karl Ottenstein — Mon, 14 Feb 2005 20:11:26 GMT

Again, for our student, here is the result of creating an ArchiCAD material using the resulting texture image and applying it to the "Sofa 03" library part.

You can see a few issues with the result. The image repeats seamlessly, but there is a stripe (pointed out with arrows) that is darker than the rest of the fabric ... this is because I didn't take the photo in a location with even lighting. [Edit: see Dwight's post on 'pulsing'... posted while I was typing this! Thanks Dwight!]

Within that dark stripe, you can see a repeating little dark "glob" ... something that could have been fixed in Photoshop.

The most unsatisfactory problem is the way the fabric wraps onto the arm of the sofa. You'll see that the pattern on the top of the back and top of the arm all aligns, but the side of the arm is offset. This is an issue with the actual GDL library part and cannot be fixed without GDL coding. A similar thing happens in the curved part of the back, the stripes align, but the pattern is shifted up. No user control over this.

Karl

Re: folded or crumpled textile

Anonymous — Thu, 17 Feb 2005 13:46:26 GMT

Now all I have to do is have ago myself, one of these days.

Julia

Re: folded or crumpled textile

Aussie John — Thu, 17 Feb 2005 21:44:40 GMT

yep all these things take time and there always is a hiccup along the way to make it take a lot longer than you hoped. Once it is done though it then becomes a time saver or gets the result you want. I have to confess to spending way too long get some library parts to work but in the long run has been worth it