Adjusting position of a texture on a curve surface

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mjdog

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May 20, 2012, 10:45:07 PM5/20/12
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I'm working on a model that has a cylindrical tower in one corner, with three stories of windows.  I have a decent photograph to use for its surface, but when I apply it, it is not in the correct position, and (unlike flat surfaces), when I right-click the texture there is not the usual "Textures > Position" option.    Am I missing something, or is this a weird issue with curved surfaces?

SnowTiger

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May 20, 2012, 11:44:04 PM5/20/12
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Here's a couple tricks to keep on hand.

As you probably already know, any circle or cylinder is made up of multiple faces (i.e. not a true round or circle).
As such, faces are angled on different angles.  That said, it is important that the face that you sample the projected image from is parallel with the face you want to texture. Furthermore, that sample plain must also be located directly 90 degrees perpendicular to (or straight out from) the face which is to be textured with the projected image (or as close as possible).
So there are many times when I have to place my image (the one which is to be projected) onto a flat plain then I will make copies of that textured plain in an array or whatever so that they are positioned as described above.
Then you sample the corresponding adjacent "projected texture sampling plain" (for lack of a better name/description) and texture the surface(s) that are closest/adjacent.
Do this for each face or geometric tile (Hidden Geometry ON) that is needed.
AND
Whenever I am projecting an image onto a Spherical surface (or even cylindrical, depending on the number of faces), I might also turn Hidden Geometry ON so that I can select and texture only those geometric tiles (for a lack of a better description).
That is how I textured the following water tower tanks.

Water Tower Example 1
Water Tower Example 2
Water Tower Example 3

Most of the tank is textured with the terrain image or a tiled texture that I have created from a photo. However the Name Text and/or Logo Images are only projected on a few faces or geometric tiles which I could see and select with Hidden Geometry turned ON.

I hope this is the kind of answer you were looking for !!?

StrayKatStudio

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May 21, 2012, 1:42:46 PM5/21/12
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Chris, I think you meant *Plane*, Like a "flat" surface, not *Plain*, like an "ordinary, dull" surface. =)

Still, that's a fair explanation. Especially the technique of multiple photo-projections and turning on hidden geometry.

SketchUp 8 for Dummies by Aiden Chopra also has a pretty good section on this technique. With photos!

isidro del pino

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May 21, 2012, 5:44:26 PM5/21/12
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con la textura que tienes puedes proyectarla sobre el modelo,pero en los angulos donde termina la proyeccion se van a ver estirados,usa la textura,aplica la testura sobre una superficie plana y vertical,sobre ella raton derecho,convertir en textura unica,vas a materiales y alli la tendras,la superficie curva le aplicas suavizar aristas a cero grados,con esto consigues que la superficie curva se sectirize y asi podras usar la textura en cada sector,para cuadrar la foto es facil,raton encima del sector que quieres mover la textura,textura situar,aparece unos clavos y los encajas donde quieras,asi en cada cuadro,al finalizar suavizar aristas a 35 grados ,desaparecen los sectores y se queda una curva bien definida,el resto te toca practicar,conseguiras modelos perfectos

SnowTiger

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May 21, 2012, 7:00:31 PM5/21/12
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So much for my spelling eh ?
I always thought "plane" was the airplane type and plain was flat like prairies.
I never even though of plain as in ordinary.

I guess that's why my mother (English Teacher) was always marking up my "final version" of reports with Red Pen ... requiring me to rewrite everything.
My spelling was never too bad but my grammar always did and still does suck.

mjdog

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May 23, 2012, 2:19:25 AM5/23/12
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Thanks Snow Tiger, but I'm having a hard time understanding your technique.   Are you saying that if I have a cylinder with 10 sides, I need to start by create a plane perpendicular to each face???  Something like this picture above?

 I have a feeling I'm really misunderstanding this.    Do you have an image (or video) that can illustrate your technique for me.
.

SnowTiger

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May 24, 2012, 8:50:24 AM5/24/12
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Hi mjdog

I'm not surprised. I don't explain things that well sometimes.
However, the fact is you are SO Very Close to what I was "trying" to describe.

If you take each of those flat planes and rotate them along the Blue Axis about their Center, they will each be Parallel to the face each will texture as well as 90 degrees out away from that face.

Hopefully this helps a bit.
If not, let me know ASAP and I'll try to upload a 3D Model Tutorial to the 3DWH before Noon.

Scorpius

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May 24, 2012, 6:12:08 PM5/24/12
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You can always go on view and check Hidden Geometry now you can see curved faces in segment.
Now you can add texture on each segment of curved faces,like you adding texture on flat wall,need some patience to tune it but it's manageable.

SnowTiger

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May 27, 2012, 11:05:22 AM5/27/12
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BTW - If you don't see the option to Position your texture, it's likely because the texture has been Projected. Thus you'd have to turn off Projected to be able to manually position the texture.

BTW Again - Something else I should have already mentioned is that the method I "tried" to explain previously, depends on what you are trying to texture with.
It will work great with something like brick or siding, but not necessarily so well for windows (especially if the windows aren't supposed to be on all 10 sides of your cylinder).

Let me know if you are still having issues with this situation.
I'd gladly hook up on G+ Hangout (or the like) to tutor you through several options if you like.
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