>> On the other hand, weren't you the guy complaining that "propper 3D 
>> CAD programs" are too crash-happy?
> 
> Not me, I can't remember the last time Catia crashed on me.  Don't ask 
> me about the thermal simulation software I use though...

The only CAD program I've ever heard of is AutoCAD. Last I checked, it's 
slightly expensive. ;-) Then again, given that it's complex specialist 
software with a limited market demand...

I doubt I'll ever need to simulate thermals. Mechanical stress, on the 
other hand...

(Do you have any idea what the "bending moment of reinforced concrete" 
is? I haven't.)

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> Last I checked, it's slightly expensive. ;-)

I have no idea about AutoCAD, but I think a base license of Catia is about 
5K.  For personal use, ermm, no not really :-)

> I doubt I'll ever need to simulate thermals.

Me too :-) But in my job I do.  A few weeks ago we had to choose between two 
microprocessors, the standard 85 degree C max version, or the special 125 
degree C max version.  Obviously there's a price difference, and our product 
must work up to 75 degrees ambient.  Do we order the 85 degree version or 
the 125 degree version?

> (Do you have any idea what the "bending moment of reinforced concrete" is? 
> I haven't.)

The material doesn't matter, bending moment is just a description of the 
internal torques of a bent object.  If you cut a bent object (eg a bent 
ruler) obviously the two halves would spring back to their normal flat 
shapes, the bending moment is the torque you would need to apply to each 
side of the cut to keep the original bent shape.

If you're mathematically minded, you can calculate lots of interesting 
things by repeatedly integrating any applied forces to the object with 
respect to distance.  The first integration gives you the shear force in the 
object, the second gives you the bending moment, the third gives the 
curvature (multiplied by some constant) and the fourth gives you the 
deflection.  The constant you need depends on the cross-sectional shape and 
the material properties, but it's relatively straightforward to look up 
and/or calculate.

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>> Last I checked, it's slightly expensive. ;-)
> 
> I have no idea about AutoCAD, but I think a base license of Catia is 
> about 5K.  For personal use, ermm, no not really :-)

LOL! OK, where's my latest Insight spam... OK, Autodesk AutoCAD LT 2010, 


I'm *so* not trying that. :-P

>> I doubt I'll ever need to simulate thermals.
> 
> Me too :-) But in my job I do.

Yeah, well, you make small hot things, right? ;-)

>> (Do you have any idea what the "bending moment of reinforced concrete" 
>> is? I haven't.)
> 
> The material doesn't matter, bending moment is just a description of the 
> internal torques of a bent object.  If you cut a bent object (eg a bent 
> ruler) obviously the two halves would spring back to their normal flat 
> shapes, the bending moment is the torque you would need to apply to each 
> side of the cut to keep the original bent shape.

I was chatting to some guy who apparently designs bridges and so forth. 
Maybe not "bridges" as such, but things like motorway flyovers, ramps, 
etc. Apparently it's kind of important to know about such things...

Personally, I know very little about this kind of thing. Although I did 
read somewhere that at high speeds, materials behave as if they are 
harder and more brittle than they are. Which would explain why jumping 
belly-first into a pool of soft, liquid water is so God-damned painful. o_O

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> LOL! OK, where's my latest Insight spam... OK, Autodesk AutoCAD LT 2010, 

>
> I'm *so* not trying that. :-P

There used to be a free version of ProEngineer called ProDesktop which was 
really good.  Unfortunately they stopped that line for some reason, and now 
there seems to be nothing available for home users in terms of quality 3D 
CAD.

> I was chatting to some guy who apparently designs bridges and so forth. 
> Maybe not "bridges" as such, but things like motorway flyovers, ramps, 
> etc. Apparently it's kind of important to know about such things...

I would imagine so, you don't want a motorway flyover collapsing because a 
queue of heavy trucks stops on it.  Also important to know how much your 
bridge is going to expand/contract based on temperature and design for that, 
otherwise you'll end up with a buckled road...

> Personally, I know very little about this kind of thing. Although I did 
> read somewhere that at high speeds, materials behave as if they are harder 
> and more brittle than they are. Which would explain why jumping 
> belly-first into a pool of soft, liquid water is so God-damned painful. 
> o_O

When you test the hardness of materials you generally apply the force quite 
slowly, so can I well imagine that applying forces at a similar speed to 
that which the material can deform will result in a seemingly much harder 
material.  I suspect for things like road surfaces they generally test with 
real life stuff and don't just go on the suppliers hardness rating. 
Although you never know, when they built the Newbury bypass they had to do 
it again a year later because the trucks had ripped up the surface.

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>> LOL! OK, where's my latest Insight spam... OK, Autodesk AutoCAD LT 

>>
>> I'm *so* not trying that. :-P
> 
> There used to be a free version of ProEngineer called ProDesktop which 
> was really good.  Unfortunately they stopped that line for some reason, 
> and now there seems to be nothing available for home users in terms of 
> quality 3D CAD.

Well, I mean seriously, it's not like I'm DESIGNING AND BUILDING A PIPE 
ORGAN FOR MY HOUSE. [I'd just like to emphasize again that SOMEBODY 
ACTUALLY DID THIS.] I just like building stuff for fun. ;-)

>> I was chatting to some guy who apparently designs bridges and so 
>> forth. Maybe not "bridges" as such, but things like motorway flyovers, 
>> ramps, etc. Apparently it's kind of important to know about such 
>> things...
> 
> I would imagine so, you don't want a motorway flyover collapsing because 
> a queue of heavy trucks stops on it.  Also important to know how much 
> your bridge is going to expand/contract based on temperature and design 
> for that, otherwise you'll end up with a buckled road...

Well, when you see a huge bridge over the river Severn or something, 
it's obvious that some serious engineering went into it. But a small 
ramp up a hill? How hard could that be? Quite hard, apparently...

It still blows my mind that in some parts of MK, you drive down a road 
and there's a road crossing 30 feet below you, and a few yards later 
another road crossing 30 feet above you. And all of these roads are 
roughly level along their entire length, and level with the surrounding 
ground plane. That must have taken some *serious* hard-core earthworking 
to do in the first place...

>> Personally, I know very little about this kind of thing. Although I 
>> did read somewhere that at high speeds, materials behave as if they 
>> are harder and more brittle than they are. Which would explain why 
>> jumping belly-first into a pool of soft, liquid water is so God-damned 
>> painful. o_O
> 
> When you test the hardness of materials you generally apply the force 
> quite slowly, so can I well imagine that applying forces at a similar 
> speed to that which the material can deform will result in a seemingly 
> much harder material.  I suspect for things like road surfaces they 
> generally test with real life stuff and don't just go on the suppliers 
> hardness rating. Although you never know, when they built the Newbury 
> bypass they had to do it again a year later because the trucks had 
> ripped up the surface.

They were saying that if, say, a bullet hits things, they tend to 
shatter rather than deform. Apparently due to the velocity of the 
bullet, the materious "doesn't have time" to deform, so it shatters 
instead. Sounds pretty weird to me, but that's Wikipedia for you...

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Invisible wrote:
> the best feature of all is the way surfaces "stick" to each other as 
> soon as they touch...

That's actually a very useful feature if you can control it. :-)

-- 
   Darren New, San Diego CA, USA (PST)
   I ordered stamps from Zazzle that read "Place Stamp Here".

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nemesis wrote:
> Invisible wrote:
>> Yeah. How SketchUp does intersection is that you line up the two 
>> objects, press "intersect", and then delete the geometry you don't want. 
> 
> Blender too.

Oh good. It's not just me.

I always thought "animation work flow" was a technique to avoid having to go 
back and change something you'd already committed to using, so you wouldn't 
have to re-do texturing just because you decide his nose is bigger, or re-do 
walk cycles because you decided he needs five fingers instead of four.

-- 
   Darren New, San Diego CA, USA (PST)
   I ordered stamps from Zazzle that read "Place Stamp Here".

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Invisible wrote:
> Trace it in 2D, extrude into 3D, cut out a few 
> rectangular doors and windows, in about 30 minutes total you have a true 
> 3D model of the main parts of this house...

There's a guy who shows you how to do this in Blender, too. I tried it, and 
it's pretty straightforward. I can find the videos if you care. :-)

-- 
   Darren New, San Diego CA, USA (PST)
   I ordered stamps from Zazzle that read "Place Stamp Here".

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>> the best feature of all is the way surfaces "stick" to each other as 
>> soon as they touch...
> 
> That's actually a very useful feature if you can control it. :-)

Sometimes it's useful. Frequently it isn't. Especially given that it's 
usually unexpected, and once they're stuck it's apparently impossible to 
unstick them...

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Orchid XP v8 escreveu:
> manually, delete the faces you don't want any more. One at a time. You 
> see, any curved surface becomes 25,000 polygons, which you must delete 
> individually, one at a time.

haha, stop being crazy, dude.  You surely have some sort of "block" 
select or edge loop to region thing which will select countless in a 
single move.

> So, now you have one pipe. But I want 23 pipes. So, first select the 
> pipe and ask SketchUp to make 12 copies of it. (Fortunately, there *is* 
> an automatic way to do this!) Now select 11 of those copies, and make 
> them all 5% smaller. Select 10 copies, make them all 5% smaller. Select 
> 9 copies. Make them all 5% smaller. (Are you bored yet?) Eventually, you 
> have 12 pipes, all different sizes. Now the fun part. Copy them, 
> reposition the copy. Mirror it. (Do NOT rotate it as I mistakenly did!) 
> Spent 20 minutes trying to make it line up properly with the existing 
> pipes.

There's surely a faster and simpler workflow for that.  I'm sure you 
didn't get into a Haskell expert in a single weekend.

> I can't help but feel that POV-Ray could have done this radically 
> faster. And the pipes would be *real* cylinders, not 24-gon prisms. And 
> they would be *shiny*!

They will be shiny once you export them for povray to render. ;)

-- 
a game sig: http://tinyurl.com/d3rxz9

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