[Genma Saotome]

The Cherry Street Bridge is the means whereby trains reach Goose Island. It's an interesting structure... a bobtailed, pin-linked truss bridge. IOW, just half of a normal swing bridge. It's been recorded in the HABS-HAER archive at the Library of Congress and there are numerous photos on the web and so reference material was readilly available.

I've got only a couple more polys to add to the structure... here are a few screenshots taken inside Sketchup:













The large concrete block is the counter-weight to the rest of the bridge so everything is balanced on the turning mechanism.

I figure that as most activities will involve crossing the bridge twice it needs to look good and so it's built with a lot of detail included: a handful less than 13,000 polys and so I have extensively used LOD's... almost half of the polys are culled outside of 250m and I'm still working the problem (my goal is to have a LOD on everything 8 inches wide or less, which is almost done but I've not really examined the issue of water facing polys... I expect I'll get quite a few more there set to very short LOD's).

[Bernie]

That's a very intricate model, and the early weathering you have applied is very realistic, well done! :)

[Fred]

Absolutely beautiful Dave!http://www.elvastower.com/forums/public/style_emoticons/default/clapping.gif

I can appreciate the skill required for such a bridge. Several years ago I tried to create a cylinder for a steam engine boiler. It looked like my four year old grandson drew it with a crayon.

Keep up the good work.

[Mipman25]

Fantastic looking bridge, Dave.

[TheArkerportian]

Impressive, indeed! I wonder what it will look like in service!

[mrbreeze]

Were you thinking of animating it or is it purely a fixed model?

[Genma Saotome]

Static.

Isn't animation accomplished by storing all the vertex data for whatever is moving for each point in time? The .s file would be huge if I were to animate it... my mind boggles at the thought of the potential byte count.

If you want to read more about the bridge, here is the Wikipedia page and here are far more photos of it than you can imagine anyone taking... but they did.

[wacampbell]

Genma Saotome, on 15 January 2014 - 02:58 PM, said:

Static.

Isn't animation accomplished by storing all the vertex data for whatever is moving for each point in time? The .s file would be huge if I were to animate it... my mind boggles at the thought of the potential byte count.

If you want to read more about the bridge, here is the Wikipedia page and here are far more photos of it than you can imagine anyone taking... but they did.

Animation adds only about 10 lines to the .s shape file - maybe a couple of hundred bytes at most. This bridge rotates about a pivot. What gets stored is the initial rotation angle and the final rotation angle, both expressed as quaternions. That's all. The CPU interpolates the quaternions for the correct angle at any given frame of the animation ( simple math ), and then the GPU handles transforming each vertex based on the needed rotation. That last step adds no work load to the GPU as it already has to do a transformation based on the world coordinates for the object and any hierarchical structure in the model.

[Coonskin]

Wayne Campbell:

You is so smart and I are so dumb. :sign_thanks:

(HOW did you learn all that stuff????)

[Genma Saotome]

:sign_thanks:

What Andre said.

:D