Forums Technical Discussion Default PolyWire UVs

Default PolyWire UVs

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DASD
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Hi!

1. Is there a way to get the automatic UVs from PolyWire SOP without any overlap? (Please see UVs in polyWireExample).

2. Is there a way to get PolyWire automatic UVs to get automatically sewn along uninterrupted lines?
For example, in polyWireExample2, I would expect 3 UV shells. Ideally the SOP would create just 2 non-overlapping UV shells in this case, but a method that would create 3 would probably be more simple and more stable.

3. Is there a way to get PolyWire automatic UVs that are proportionally scalled to the lenght and radius of the poly wires?

Attachments:
polyWireExample2.hiplc (55.1 KB)
polyWireExample.hiplc (49.9 KB)

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Enivob
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There are some example files here on this topic.
http://forums.odforce.net/topic/23174-cables-over-cables-uv-problem/?hl=cables [forums.odforce.net]
Using Houdini Indie 20.0
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DASD
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Thank you Enivob!
I was aware of the “copy and skin” and the “sweep” methods. But I specifically want to use polywire, because it is fast, gives good topolgy and can resolve branching lines with nice corners.
But by looking at these methods again, I realized that I can measure polylines and then use the resulting parameter to drive the “textv2” parameter on the polywire SOP to get the right proportion in lenght. Additionally I can put the circumference of the tube into the “textu2” parameter and I get the proportions perfect.
After that I discovered that I don't even have to use a measure node and can put $PTDIST in the “textv2” parameter.

Now I know I need to put something in the U Seam Offset, to prevent “crumbled up” UVs, but I can't quite figure out what.

Questions 1 & 2 are stilll open. Question 3 is resolved.^^
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scorpes
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I'm also interested in a solution for question 3. Did you made any progress?
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Enivob
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I'm not sure if you can get totally seamless where wires branch but F1 has posted an example file related to UVs and Polywire. Maybe there are some techniques contained in the example file you can leverage.
http://forums.odforce.net/topic/31049-how-to-properly-transfer-the-uv-map-from-a-high-poly-to-a-low-poly/?do=findComment&comment=172926 [forums.odforce.net]
Edited by Enivob - Sept. 1, 2017 08:32:00
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DASD
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Hi,
I looked at my post, again, and then I looked at the stuff that Enivob linked (file by f1480187).

Attached is what I came up with.

Note that you can go beyond this level of control, but I think I sufficiently show the tools at your disposal.

All manners of upgrades, discussions, performance improvements and expansion are welcome. XD
Edited by DASD - Sept. 3, 2017 08:51:09

Attachments:
branch_uvs v2.hipnc (262.5 KB)

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Olaf Finkbeiner
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Hi DasD,
maybe not realy what you want but…
I have made a version with a different approach…

Attachments:
string_sweep_uv.hipnc (364.4 KB)

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DASD
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Great solution Olaf! With a boolean node at the end you can even get somewhat decent intersections for this case.
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Olaf Finkbeiner
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HI DasD,
yes and you could even sync the position of the branching by doing a layout of the individual segments, so they would fit better…
I just did not need that right now…

And yes of course a boolean at the end would make it even nicer.

glad that you like it.

Olaf
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m4x
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Olaf,
thank you for your solution (I really like the clear way you present your approaches)

Theres only one thing: I wonder why the UV Projetion has to be scaled down by the exact number of 0.2?

Max
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mackerBaehr
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Hi DasD

Struggling with the same problem but in this case with a closed curve to polywire I came up with the following solution, which assumes you have your inputcurve re-sampled at even distances.

Append to the polywire a vertex wrangle with this line:



The number 16 stands for the amount of divisions of the polywire.
Now all UV's are nicely stacked instead of overlapping. Append a UV transform afterwards for proper scale/layout et voila.

Michiel
Edited by mackerBaehr - Nov. 29, 2018 08:54:50

Attachments:
uvStack.PNG (403.3 KB)

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DASD
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m4x
Theres only one thing: I wonder why the UV Projetion has to be scaled down by the exact number of 0.2?
Max

It has to do with the radius to length ratio of the polywire. The uvproject is in cylinder mode, so the radius is always mapped 0 to 1. The scale only affects one dimension and thereby effectively controls the stretching of the UVs along the cylinder. If you increase the radius of the tube, you need to adjust the scale.
To get it exact you just use ch(“../polywire1/radius”)*3.14159*2 for the scale. (3.14 etc. is Pi and we get this from https://en.wikipedia.org/wiki/Circumference).

I am working on a more complete solution. XD
Edited by DASD - Nov. 30, 2018 21:27:12
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DASD
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I think i might have solved all of it.

Attachments:
polywire_uv2.hipnc (546.9 KB)

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RichCTea
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I made a tool that does something similar amongst other things for Polywire
Fixes the both U and V coordinates mainly be looking at topology and connections - so it supports branching.

It's free and can be downloaded here: PolyWire UVs — Richard C Thomas [richardcthomas.com]

Hope it helps!
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