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[Grizzly]

Hi.

I´m trying to create some simple ring-binders ("Leitz Ordner") to populate the POV renderings of some office premises. For the back label of the binders I made some texture with gimp, saving it as a tga. The cuboid that constitutes the back of the binder is 8cm width (in X-direction) and 32cm high (in Z-direction). My texture image is 160x40 pixels. I use "Planar-Y" to fix the texture on the binders back. Now when I distribute several binders at random on a shelf, the texture is completely misaligned on most binder backs. It seems like all backs of all binders, also completely seperate 3d objects and sometimes far apart, are taken as one large canvas, and the texture is tiled over the whole imaginary plane, only sometimes accidentially aligned correctly on one binder or another. If I switch of the "repeat" option in the Material Dialogs Texture field I don´t get a texture at all on any binder´s back mesh. It gets completely transparent.

If this would help understanding, I could upload my texture and some renderings and link them here.

Does anybody know how I can do this? Have a texture projected one side of a cuboid, And have multiple instances of that "material" distributed around a shelf?

Yours,
Christian

[steve]

Interesting question. I have come across something similar. I was trying to place paintings around the walls of a room. I had some nice images (some jpgs some pngs) and created a rectangle with the polygon function which I then placed in contact with a cuboid to represent the frame. The cuboid was assigned a material (say blue) and the polygon was assigned one of my images as texture.

If the "painting" lay in the xy plane and I used defalt texture setting, all was OK. I could take snapshots with Povray from any angle. The settings planar-x -y -z give transparent images in Povray. Spherical and cylindrical produce some weird radial and linear distortions of the image which are interesting.

Then when the "painting" is oriented vertically (xz plane) I could not get any sensible image. The spherical and cylindrical settings produce the same results as above.

In the end I chose spherical and claimed that it was modern art!

Someone must have a solution to this?

[luca]

The problem exists, I can´t guess if it´s matter of cycas or pov.
A workaround can be to use walls instead of prisms or planes, the default texture projection puts the image correctly on the vertical side of the wall, repeated or not.
As a collateral effect (sometimes useful) if the image has an alpha the visible pixels are (correctly) projected on both sides of the wall and you see two images separated by the wall thickness.
ciao
luca

[steve]

Thanks Luca the trick of using a wall is good.

But I am still a little puzzled.

if i build a pitched (say 45 deg) ceiling with exposed rafters i can get a pretty good rendering of the rafters even though they are made from cuboids. i use a wood image, turn it through 45 deg using gimp, crop it back to a square image. then i use the planar-y/repeat texture settings and input to povray. then the grain runs along the length of the rafter.

It looks ok from the floor, and i can´t figure out if the image is just being smeared along the rafter. if  i use a wall to make the rafter, the rendering is different. of course changing the size of the image in the material dialog box gives a different look again. in any case it is possible to make a decent looking rafter

what are your thoughts?

[luca]

I think that texture handling should be improved, if it was possible with object local coordinate alignment, texture overloading, rotating and origin shifting.
This would give an easy way to handle common representation problems in building construction and interiors, without wishing to unnecessarily transform cycas in a full featured 3d modeler/renderer interface.
I don´t know if it is possible or not due to my (deliberate) ignorance of pov and (obvious) in cycas internals, but some improvements would be appreciated.

About your procedure of rotation, cropping with gimp ecc. it is good, I think I´ve used something like that for some floor textures in non orthogonal rooms, but I wasn´t happy about that, it takes a lot of time ... but I think it´s the only way...
ciao
luca

[steve]

I like the improvements that you suggest for texture mapping. I suspect that all things are possible if one gets inside povray, but it does seem daunting. I may have a look someday.

Anyway I feel that no software can do everything perfectly and that we still have an excellent and unique architectural tool in Cycas.

Also when I look at the images created on Anja and Wolfgangs website...I don´t know how much was done in cycas and how much in other apps...what more could one need?

By the way it´s very quiet on the forum these days. Is it summer holidays over there in Europe or what?

[acfrese]

Hello!

... it is quiet in October? Sure, there are the autum hollydays comming up. rolle

...anyway, we designed a small example trying to clear up the problem m.a. It is a sign that can be viewed from both sides. Two .tga graphics with transparency are sticking on wall elements. You can look into the setup of the materials - it is default, it is defined by size (same size as the wall-elements).

http://www.papierdrachen.de/trans/logo_howto.tar.gz

Copy
the materials m_logo_runda1 and m_logo_rundb1 into your /CYCAS3/dia/mat
the texture graphics logo_1a.tga and logo_b1.tga into your /home/CYCAS3/tex

@ steve
... the pictures in the gallery are rendered in CYCAS. Some were composed with The Gimp - especially the graphics showing the real site and the rendered image in it. In room 5 there are some graphics that were rendered with Radiance.

Best Regards,  Anja C. Frese

[luca]

Exactly... one file is better than many words  
For giving form to all this, here is a link to this symbol I´ve made some time ago, it´s a light weight tree taken off 2 walls, I´ve packaged everithing is needed...

http://www.aui-architettura.it/download/albero.tgz

as said before the collateral effect of the two side projection of the image gives a nice motion blur effect...

ciao
luca

p.s.
the images in the gallery are really good...

[steve]

Thanks Anja for that example. The use of the wall elements and the transparency will be useful. I will also be trying out some more ambitious compositions using Cycas/Povray images and Gimp.

And Luca, your albero example is excellent. I once downloaded a model of a tree and when I opened it there were just these few blank flat planes...of course the image must have been there somewhere. Now I know the secret! Thanks for that.