making material with a unique pattern

[Anonymous]

hi
i'm trying to make a round carpet which will have a picture on it- not a repeating pattern but a very specific logo i have of the client. is it possible in ac 15?

[Laszlo Nagy]

I think it is possible.
In the Materials Dialog, you will need to manipulate the Texture you assign to the Material.
Lets say the bounding box of your round carpet is 3x3 meters. Then you should create a image which will be this 3x3 meters in size. This way only 1 tile of the Texture will be visible on the carpet. ArchiCAD will tile the texture so you make the unit size of the texture as large as the element you apply it to, this way the tiling will not appear.

The image should be an image with alpha channel (e.g. 32-bit TIFF). The image should contain the picture you want to appear on the carpet, and all the rest should be white pixels (or black, I am not sure at the moment whether it is black or white that is considered fully transparent when used in the alpha channel). Then you need to check the Transparency checkbox in the Texture panel of the Materials Dialog to use this alpha channel information.

[Karl Ottenstein]

To clarify a little on the answer that Laszlo gave... the reason for the alpha channel and invisible pixels around the round (ellipse, whatever non-rectangular shaped) image is so that you can align a rectangular texture onto a rectangular object... and then see only the round carpet... not the rest of the rectangle.

You would apply this texture to a very thin slab. It should automatically align properly. If not, use the Align Texture in 3D command to snap it to a corner.

The alpha mask will only be effective in a rendering... in the OpenGL window or BIMx, you will see the full rectangle unless you trim it with a solid element operation.

[Laszlo Nagy]

Or you can made the carpet object round to begin with and you will not have to trim it to round shape with SEO.

[Karl Ottenstein]

laszlonagy wrote:
Or you can made the carpet object round to begin with and you will not have to trim it to round shape with SEO.

My experience is that textures will not align properly to non-rectangular objects... unless the texture 'anchor' (typically a corner) exists. Would love to know that it works now for round objects though.

[Laszlo Nagy]

I see. So this is the reason you suggested to do a rectangular object and then perform SEO on it. I did not know that quirk of the program. (Although I would think it should not be that hard to align the Texture in 3D if it does not align properly to the round object.)

[Karl Ottenstein]

The Align 3D handle/anchor is a corner. Unless things have changed since I last did it. Not like Artlantis where the handle can be user-positioned anywhere and the texture freely dragged... or for that matter, simply overlaid on top of another texture.