Arch Bridge and Other Bridges. New: Cable Stayed.

richardandtracy

Just a sneak preview of my freebie bridge inspired by ancient Chinese Arch bridges. Feel I have learnt a lot with modelling this up. I was really pleased to be able to get the straight block texture to curve around the arch given that I only have UVMapper free as my texture mapping package. There are not a lot of facets, I think there are only around 150 or so, but it has been a challenge.

Just a few days more before I can package this up as a freebie.

Regards,

Richard.

AOBB

Impressive! Most impressive! 

richardandtracy

Thank you AOBB. I do hope it'll be useful once people can download it.

At the moment the texture files are 2k for the diffuse & 1k for everything else. I think I may offer a 4k diffuse & 2k everything else high res material option. The image above uses the 2k/1k mix. This is the first time I have tried Poly Haven CC0 license textures on a freebie, and they really are very good - much better than my attempts at a seamless texture.

Regards,

Richard.

lukon100

I like the way it looks. Seems to me this will be an awesome freebie.

lukon100

This is the first time I have tried Poly Haven CC0 license textures on a freebie, and they really are very good - much better than my attempts at a seamless texture.

As I look at the textures I imagine myself making the UV maps for this bridge in Blender, wherein the curved stones would have to be allinged using that "UV Squares" plugin. Makes me wonder whether that is precisely what you did.

perlk

This looks amazing, thank you for offering it!

crp

Looks great!  Can't wait to use it.

richardandtracy

lukon100 said:

This is the first time I have tried Poly Haven CC0 license textures on a freebie, and they really are very good - much better than my attempts at a seamless texture.

As I look at the textures I imagine myself making the UV maps for this bridge in Blender, wherein the curved stones would have to be allinged using that "UV Squares" plugin. Makes me wonder whether that is precisely what you did.

I admit it was a bit of mental gymnastics to work out how to get the model to UV map properly, especially as my residual anti-virus on my offline Win7 machine prevents me from using Blender or B4Artists (which I prefer on principal as there is a menu option for every function).

1. I put a split line in the model in SolidWorks just to make sure there were facets in the right place on the bridge side walls at the depth of the curved arch stonework (90cm).
2. I exported it in .stl format and converted to OBJ using a program I wrote.
3. Then in my own home written modeller I de-triangulated it as much as was sensible and applied the material zones and all the flat surface texture mapping except on the edge of the arch.
4. At this point I split the model into two and worked only on the arch, with the arch and the curved bricks on either side forming part of a tube with a flange at either end. 
5. I translated the flange vertices furthest from the arch aperture along the axis of the arch so that they were now 90 cm from the desired edge of the bridge - same as the depth of the curved bricks. This left a cone shape on either side of the arch.
6.  Then I scaled the vertices so the curved bricks now formed an extension to the inside of the arch. In this case the scale factor was 83.3333%.
7. This model was then exported to OBJ and used in UVMapper Free to have a cylindrical map. Saved as an obj file and imported back into my modeller.
8. The curved brick vertices were then scaled by 120% to get them back to the right diameter (forming a cone on either side of the arch) and translated to the correct position in line with the sides of the bridge to form a flange of facets on either side of the arch.
9. Finally the arch model and remainder model were merged and vertices welded to make a single model again.
10. Now the whole bridge could be exported as an obj to DS and materials applied.
11. Job jobbed.

It actually sounds harder than it was. The difficult part was thinking how to do it at all. During my first attempt I exported the arch to UV Mapper at the cone stage (missing stage 6), and that led to non-radial block joints, whose angle varied around the arch. That looked totally wrong. Going back and adding stage 6 (and reversing it after tex mapping) meant the joints went radial again.

Until I thought of a way of doing it, I was trying to think of the problems associated with writing a method to do radial tex mapping for my modeller - but fortunately that wasn't needed.

I'd sort-of like to model this bridge near the Leshan Buddha:

But... It would be a heck of a task, and as it's so famous there is a risk of being flamed for 'Cultural Appropriation', even though it'd be more of cultural advertising. And trying to get a reasonable gorge for it - well, I simply can't model anything like that.

Ah well, we can all dream.

Regards,

Richard.

 

 

richardandtracy

The 60Mb zip file is now available to download from my Renderosity freebies. The link is visible in the signature line at the bottom of the desktop version of this post. Regards, Richard.

Catherine3678ab

Thank you very much :-)

lukon100

richardandtracy said:

lukon100 said:

This is the first time I have tried Poly Haven CC0 license textures on a freebie, and they really are very good - much better than my attempts at a seamless texture.

As I look at the textures I imagine myself making the UV maps for this bridge in Blender, wherein the curved stones would have to be allinged using that "UV Squares" plugin. Makes me wonder whether that is precisely what you did.

I admit it was a bit of mental gymnastics to work out how to get the model to UV map properly, especially as my residual anti-virus on my offline Win7 machine prevents me from using Blender or B4Artists (which I prefer on principal as there is a menu option for every function).

1. I put a split line in the model in SolidWorks just to make sure there were facets in the right place on the bridge side walls at the depth of the curved arch stonework (90cm).
2. I exported it in .stl format and converted to OBJ using a program I wrote.
3. Then in my own home written modeller I de-triangulated it as much as was sensible and applied the material zones and all the flat surface texture mapping except on the edge of the arch.
4. At this point I split the model into two and worked only on the arch, with the arch and the curved bricks on either side forming part of a tube with a flange at either end. 
5. I translated the flange vertices furthest from the arch aperture along the axis of the arch so that they were now 90 cm from the desired edge of the bridge - same as the depth of the curved bricks. This left a cone shape on either side of the arch.
6.  Then I scaled the vertices so the curved bricks now formed an extension to the inside of the arch. In this case the scale factor was 83.3333%.
7. This model was then exported to OBJ and used in UVMapper Free to have a cylindrical map. Saved as an obj file and imported back into my modeller.
8. The curved brick vertices were then scaled by 120% to get them back to the right diameter (forming a cone on either side of the arch) and translated to the correct position in line with the sides of the bridge to form a flange of facets on either side of the arch.
9. Finally the arch model and remainder model were merged and vertices welded to make a single model again.
10. Now the whole bridge could be exported as an obj to DS and materials applied.
11. Job jobbed.

It actually sounds harder than it was. The difficult part was thinking how to do it at all. During my first attempt I exported the arch to UV Mapper at the cone stage (missing stage 6), and that led to non-radial block joints, whose angle varied around the arch. That looked totally wrong. Going back and adding stage 6 (and reversing it after tex mapping) meant the joints went radial again.

Until I thought of a way of doing it, I was trying to think of the problems associated with writing a method to do radial tex mapping for my modeller - but fortunately that wasn't needed.

I'd sort-of like to model this bridge near the Leshan Buddha:

But... It would be a heck of a task, and as it's so famous there is a risk of being flamed for 'Cultural Appropriation', even though it'd be more of cultural advertising. And trying to get a reasonable gorge for it - well, I simply can't model anything like that.

Ah well, we can all dream.

Regards,

Richard.

Osum! Nobody else has that workflow. So I magine part of the fun you have making free models is getting to use the tools you programmed yourself.

That Leshan Buddha bridge sure is fancy and pleasant to look at. Perhaps you could make a simplified version inspired by it.

richardandtracy

I suspect nobody has that workflow because it's plain mad. All the program tools I've written are available elsewhere on the web, but as they were written for me, they suit me and may not suit anyone else. My modeller was started in 2004 so I could work more quickly in creating stress models than when using the 1990 origin modeller that came with the NISA Finite Element Stress software. It has been made redundant for that purpose, so I adapted it to work with.obj files as I have no other interface between CAD and DS. Regards, Richard.

Fishtales

Looks like the Packhorse Bridge in Carrbridge :)

https://www.scotlandinfo.eu/old-packhorse-bridge-in-carrbridge/

richardandtracy

It looks very similar, doesn't it? Similar shallow thickness arch. Regards, Richard.

Fishtales

richardandtracy said:

It looks very similar, doesn't it? Similar shallow thickness arch. Regards, Richard.

 A lot of that bridge has disappeared over the years with high water :)

https://www.bbc.co.uk/news/av/uk-scotland-49267605

ed3D

looks  cool  _._

richardandtracy

@Fishtales : Looks like the river on the edge of my parents farm. Had an annual flood or two like that, coming up over the lane at either end of the bridge.

@ed3D : Hope you find it useful.

Regards,

Richard.

ed3D

richardandtracy said:

@Fishtales : Looks like the river on the edge of my parents farm. Had an annual flood or two like that, coming up over the lane at either end of the bridge.

@ed3D : Hope you find it useful.

Regards,

Richard.

Alrite then  ,  thanx 

BronzeDragon

Very nice Richard. Sure I can find a use for it. Thanks much.

barbult

This is a nice bridge. The morphs are particularly handy. I've never seen that on a Daz prop before. I put it in an UltraScene.

I have a couple questions about the surface settings. The road bed and cap stones came out very white and bleached out in my render, while the sides looked great. Is it intended to by that white? Is it just my lighting? While trying to figure out why it was so white, I noticed that all the surfaces have Dual Lobe Specular Weight maps, but the weight is set to 0.00, so those maps won't do anything, will they? I wondered if those maps were intended to go in a different place or whether the specular weight was supposed to be something other than 0.

Catherine3678ab

The thought of trying ultrascene briefly crossed my mind but think I'll wait for a new computer to handle all that.

So I tried the bridge with an image and a plane for some Irish Green Water BUT I am pretty sure I need to work on the lighting or something too.

At any rate, yes the bridge loads with no error messages and the morphs all work :-) Thanks again Richard.

richardandtracy

Barbult, I can be particularly dense, I hadn't noticed that the specular was set to zero, just thought 'yippee, I've got texture maps, stick them everywhere'. Yep, they should have a value and setting attached. However my promos were done with the settings in the materials provided. As for the brightness of the paving stones. You have me there. Are you using sun/sky lighting close to midday? My attempts were at 16:00 hrs at the earliest, maybe I should have tried nearer midday. I will have a few tries tomorrow (it's currently after my bed time) to see any effects I can create or cure. Regards, Richard.

richardandtracy

Catherine, the white stone settings are very light. As I said to Barbult, I will have a go tomorrow to see if I can get something similar and then cure it. It'll be nearer 24 hrs from now than 12, just to put a timescale on it. Regards, Richard.

Catherine3678ab

No worries, Richard, I hadn't realized the setting was at zero either ;-)

 

 

barbult

Yes, I was using sun-sky at 11:30 AM. It is basically the default lighting provided with the UltraScenery product.

If you reevaluate the surface settings, I would suggest dropping the displacement. Iray displacement is not useful on such low resolution mesh. Look closely at renders and see if the displacement is doing what you expect. I think it is not.

Thanks for noting the texture map source and usage rights in the readme.

I modified my scene. The bridge is in much more shadow now. I darkened the base color of the light surfaces and added some dirt overlays. It blends in nicely now.

Catherine3678ab

That looks cozy in the forest :-)

 

barbult

Ooooh, that's a steep bridge.

richardandtracy

It is a very steep bridge. The proportions are as close as I could get to the photos I could find of ancient Chinese bridges. The only difference being the real ones have steps. But, I felt that would preclude any chance of amusing images with the bridge used as a vehicle launch ramp because a driver misjudged how humped the humpback bridge was, and there is a 'car themed' freebie challenge this month. Regards, Richard.

barbult

Ah, steps. That makes sense. It makes a good skateboard ramp without steps, too.

It is a nice bridge. Thanks for sharing it.

Fishtales

The old main road bridge into Inveraray wasn't quite as steep, but close :)

https://www.alamy.com/a-hump-backed-bridge-aopproaching-inveraray-on-loch-fyne-in-argyll-scotland-viewed-from-the-northern-approach-on-the-a83-image455557529.html?imageid=FB9F38B3-2C9E-4DF4-96E2-32DB89A5A3B1&p=189032&pn=1&searchId=9fa6a679d374fca6bcebae9caac7c16e&searchtype=0

or the Clachan Bridge known as the Bridge Over The Atlantic to the island of Seil. Tour buses ground themselves on the top sometimes.

https://en.wikipedia.org/wiki/Clachan_Bridge

richardandtracy

I have played about with various alternative shader settings. The displacement should be calculated at every pixel, but doesn't seem to be, as correctly suggested by Barbult. It seems to only be calculated at vertices and linearly interpolated between. I have also played about with roughness, reflections and glossiness, coming up with a series of settings that seem to work with 2k diffuse textures and the 11:30 morning light preset with UltraScenery. I will do a zip duf file with the 2k version and a 4k one as two additional material presets, and put it as an attachment to this thread. It doesn't warrant a new Freebie on Renderosity, and in recent months I have never managed to edit a freebie zip file on Renderosity without getting the help of a moderator there - it seems too minor an update to warrant bothering anyone else about. Regards, Richard.