Please save and re-post it in Ver 8 format. Then I can check it out.

@rbarone said:

Thanks jgb, much appreciated. C of G being the same as C of B makes sense to me. Question: how would you go about using SU to determine underwater portion? Would you do the same thing in the video or would it be everything below the C of G? I appreciate the advice very much.

Obviously you need to know and be able to draw the buoys shape reasonably accurately in SU.
Then you need to know, calculate or estimate where the waterline should be on the shape. That would be the hard part, because the total weight of the buoy is far more than just the buoyancy chamber. Assuming you know the total weight, then a solid rendition of the SU model will give you the maximum floatation available, because SU will calculate the solid volume of the buoyant part.

Then using a simple ratio of total buoyancy to total weight will give you a starting point to finding the waterline. Lets say for example, the weight is 60% of total buoyancy, then the waterline will be at 60% of the volume. That, like I said, is a starting point.

Make a note of that volume. That is the target you are shooting for. Entity Info will tell you that.

I don't know what level of expertize you have with SU, so I will explain in some detail what happens next. Ask for help if you need it.

1. Make sure you have a solid component of the buoyancy chamber.

2. Make a copy and move it away from the original. Make it "unique". That way you don't mess up the original which you may need several times over doing this.

3. Draw a square face larger than the expected waterline size on the buoy, and group it.

4. Move the grouped waterline face over the copy at about the 60% point. Make sure none of the buoys lines touch the edges of the waterline face. Make the waterline face larger if that is the case. It doesn't matter how big it is, just has to be bigger than the buoy.

5. Edit the unique buoy and select only the faces that touch or cross the waterline face. You can also "select all" of the buoys faces if you wish.

6. Do an "intersect with model". That will transfer a line where the waterline face crosses the buoy.

7. Now select only the portion of the buoy that is "below" this waterline and group it.

8. Edit this group, and select any line that is the waterline and "face" it. This will close the shape and form a solid. If it does not face, you have a missing fragment problem that happens often in SU. You will need to analyze every line and vertex on the waterline and fix those errors manually. Post the model here if you can't solve this, it can get hairpulling at times.

9. Close the group and check the volume statistic in Entity Info. Compare it to the target volume.

10. If it is "close enough" (you decide how much is close enough) then that IS your waterline.
    Use CofG to find the center of buoyancy.

11. If the volume is not close enough to target, then do a number of "Undo's" to return to where you were at step 5 before you edit. Or delete the buoy copy and get a new copy from the original, and again, make it unique. Then move the waterline face up or down a bit and repeat steps 5 to 10 till you are happy.

It is not as complex as you think. Steps 5 to 10 should take about 1 minute total, unless you have waterline gaps in step 8.

If you can't make that work for you, we can take it to the next level.

@rbarone said:

Thanks Tig! ...... but a Center of Buoyancy plugin would be awesome too. I bet other SU maritime folks would love it too. Just a thought in case someone out there get interested.

The how-to video using Solidworks is similar to the way we used to have to do it in SU before TIGS CofG plugin.

Center of Gravity and Center of Buoyancy are equivalent for homogeneous solid constructs.

If you select the underwater portion of the model as a separate solid group/comp up to the waterline, then CofG is CofB, along either horizontal axis. Obviously, the volume displaced is the tunnage. And SU gives you wetted surface as well.

With some trial and error selection of wet hull sections at heel angles (to maintain approximately equal buoyancy at heel vrs upright) you can also determine both CofB and righting moment as well.

I've done it, but it can get tedious doing the slices.

I have also done it for sail plans, by giving the sails a slight artificial thickness to create a solid, then the GofG equates to center of pressure on the sail plan. A little arithmetic gives you your required keel weight at the rail down heel angle.

CofG is also very useful in placing various objects in the vessel, such as the engine, water and fuel tanks. Setting up an EXCEL spreadsheet makes this simple to play with re-locations to compute the overall CofG compared to the CofB. This goes for fixed components as well, such as the hull, deck, cabinetry and rigging. Just make everything solids and know their densities or actual weights.

@dave r said:

It's a good idea Ralph. In my experience, though, most people won't take the time to read that sort of thing anyway. It's just easier to ask the question even in cases where it's been asked dozens of time before.

When I was working an on-line/phone tech-help site, we got so many "asked & answered many times" we setup a list of "FAQs" and their answers as a set of clippable notes.

Then it was just cut&paste for about 65% of the time. Anything "new" was added to the list at the end of the call or email answer.

When I was monitoring the old Google Sketchup (before SketchUcation) I found myself doing a quick search, cut&paste for many of the same FAQs as well, especially the near field clipping solution.

Even providing an extensive published and promoted list of FAQ's, almost nobody would take the time to look up their problem first. Like Dave R said, easier to ask..........

But, part of the problem are folks that have difficulty forming the question/problem so that they can best use a FAQ's list. We see that here many times where the post "I got a problem......" sometimes does not say what the problem is on first go-round. Language barriers are only a small part of it.

@dan rathbun said:

New for SU 2013... the SelectionTool is now the default tool, by popular demand.

(In previous versions the default tool was the LineTool.)

WOW, that means I can finally eliminate Startup.rb. A God-Send from the Sketchup folks.

I only asked for this when I first started using SU, back in 2005. Others before me, hence Startup.rb was there when I first posted.

8 years........ musta used a whole development team with prototyping s/w to fix that.

OR, maybe someone at Trimble actually uses SU and stuck a needle up someones butt to fix that.

I'm staying 8.

@numerobis said:

But you know that the clipping problem is caused by geometry being placed very far away from the origin, yes?
Even if it is only an autocad block that has been created at great distance to the autocad zero point.

What we were referring to is more correctly called "Near Field" clipping and is a direct result of the Field of View angles from the SU perceived camera (your eye) distance to the object. It has no direct relationship to the Su Origin point.

When the camera gets so close that the FOV angle becomes less than the angles to screen edge, the clipping occurs. SU has no "display computation" of any part of the drawing outside the FOV, so it disappears (clipping). Think of looking through a paper towel tube versus a cone.

Making the FOV very narrow alleviates this to a certain extent, but distorts the view when the camera/object increases to more normal distances, unless you keep changing FOV to suit.

A similar thing will happen if you zoom out from a very large object, you will also see clipping, but in this case you need to widen the FOV to avoid clipping.

Also this zoomed out clipping does have a relationship to the origin point as SU "assumes" a large distance equates to a very large model space.

Since AutoCAD has (or at least had, way back when I used it) no specific origin point, unless specified, it can fool SU into computing a very large model space and zoomed out clipping becomes more common with these imported drawings.

Postby Alan Fraser » Mon, 27 May 2013 8:22 am
"A couple of things are worth mentioning........."

A LOT of little things can be fixed in SU, as I made one example in a previous post, If they can fix the zoom-clipping in Layout, then why not in SU proper, or is it simply because we pay $$$ for Layout and $zip for Free?

@rich o brien said:

new icons, toolbar chaos fixed, better exporters/importers

If that's it, then Big Whop

But what do you want for free, eh?

@thomthom said:

On my office computer (freshly formatted) I some times "feel" a lag I don't do on the same model in SU8. Especially when SU's window has been inactive a while.
But I'm not seeing this on my home computer. Not sure what to make of it.

It probably has to do with foreground/background task allocation differences, and the fact that your office PC is probably on a LAN which introduces a lag on everything anyway.

@arail1 said:

I''m not sure what the improvement in Zoom factor is - I'm not experiencing it.
I get clipping when I zoom to a line at about 1/64" long with SkechUp 8 / Layout 8. Same with SketchUp 2013 and Layout 2013. Right at the point that the line fills about half my screen I get clipped. I've never been convinced by the workaround of scaling the model so this is a big disappointment. Maybe I'm doing something wrong.

I'm about 1/2 way through reading about this disaster (2013 Make) when I saw this post, and a follow-on answer regarding FOV, which is not as effective as ......

I had this problem in spades years ago, and Catamountain (where is she now???) offered a workable simple solution.

When you start seeing near field clipping, BACK off a lot, then TURN OFF Perspective. No need to monkey with FOV.

If you don't zoom out first, turning off perspective will zoom you out by a very large factor.

Now you can zoom back in as close as you want, and there is NO clipping no matter how close you zoom in. You can see a line segment or gap smaller than .001 inch fill the screen.

One tip though, if what you want to zoom in on is very small (natch, why else?) then select it or an adjoining entity (a face is best) so that when you are zoomed out you can find what you want easier.

After, zoom back out again before turning perspective back on.

===============

As for 2013 Make, it seems to me that it will be a long time before I switch from V8 Free.
They need to make it (no pun intended) better than V8 by a lot, not just a tiny little bit.

And that entails making/fixing stuff I use every day all the time, rather than setup tools I use very infrequently.

Realistically, how often do you play with your toolbars? Or get something from the warehouse? Or install a plugin? Versus, as an example, zooming into some entity till the screen breaks?

If they can fix the clipping issue in Layout, then there is no good reason it couldn't be fixed in SU proper.

So far as I have read in this and other posts, as well as Trimbles blogs and info,
there seems to be NO (I repeat} NO real benefit to 2013 Make (Free Equivalent??) versus SU V8 Free.

All the talk is about Pro and Layout.

In Trimbles' own description of the Make version, it very soon turns to Pro and Layout features. The only clear differentiation between Make and Free from Trimble is the Commercial Use restrictions, and this was obviously written by a lawyer, not an SU user/developer.

So can anyone please list the improvements that 2013 has over V8, and NOT ONCE mention Pro or Layout?

Just curious; What is the methodology SU uses to compute a complex shaped solid's volume?

And... what is it's margin of error?

Just a "how" will suffice, I'm not looking for the algorithm.

There are several methods, with varying degrees of accuracy. Several using a myriad of slices. SU seems way too fast to micro-slice a complex object and give an accurate value.

I'm getting to a stage in 2 of my extensive models where I have to make a fairly accurate estimate of component weights, and I need to know what level of accuracy I am getting.

What set this off was my model of a special part weighing about 22 pounds taken from a suppliers very detailed dimensioned description of it, and our comparative weight calcs were off by just under 3%. Not much you say, but 3% is 48,000 pounds of variance on my big freighter airplane project. That is almost 200 passengers and their baggage, or 300 miles in range.

I fully realize I will not get a truly accurate total weight in any of my projects. They are conceptual drawings, not shop drawings, but still, I need to be able to say I am about 1% or better in my estimations to validate the concepts as feasible, from a weight standpoint, at the very least.

@takashi_komuro said:

What advantages and functions of the Joint Push Pull ?

The major advantage of JPP over SU native Push/Pull is that where SU PP only works on individual flat faces, JPP works on combined curved surfaces made up from many flat faces.

There are 3 versions of JPP, where the thickening occurs perpendicular to the selected surface, or you can set an angle to the direction of thickening. The third is a variation of SU's PP, which I never use so no comment on its functionality.

A few tips to consider before using JPP.

1. Make sure you do an "Orient Faces" before using the tool.
   IMHO that should be a default function within JPP.

2. Turn ON hidden lines only if you want to do a selection of faces on a surface.
   Turn OFF hidden lines if you want to do the total surface.
   Alternatively, turn ON hidden lines and make the perimeter of the selected faces soft/smooth lines SOFT. That will define a surface in one selection when Hidden Lines are OFF.

3. When JPP does its thing, check the corners. Most of the lines JPP creates along the thickness are soft/smooth, and the sharp corners may not be hard, if desired. Just <Shift-CTRL-Delete> those lines to make them hard.

4. Attempting to JPP to a thickness in relation to some object in the drawing may not give you the desired thickness when done.
   The better way is to JPP beyond the desired thickness, INSPECT the shape for integrity (purple lines), then type to the VCB the exact thickness dimension desired, BEFORE you double click (or <Enter> twice).

Now that I know what to look for, it is there.

thanks.

Now it works. I had X,Y & Z at 0.0 but the origin was not in view.

What does Cpoint do? I saw no difference yes or no.

But it doesn't seem to do anything in the model.

Where's the tag going each time. I've tried to select a coord but nothing happens there as well.

@tig said:

If you want just X&Y to be displayed then I suggest you set Z to 'None' ?
You need to mess around with the tool to find the settings that best suit your needs...

Bin messin aroun.

I got the "none" to work (small yea) but there seems to be a problem with "add coord tag by dialog" dialog.

When I select it, the d-box appears, but no matter what I change, it will not go away when I hit OK. It just comes back in default. Only CANCEL gets rid of it.

What am I doing wrong??

Tig

Nice Job

I only played about 20 minutes with this, so I may seem naive (I am) to some of the capabilities of this Ruby. I've read the preamble several times, but some of it does not seem to jive with the dialog boxes.

All my drawings use the green axis as my "X" axis, red="Z" and blue="Y".
You, and I expect most everyone else, uses Red, Blue, Green as XYZ.
This puts the value I need most in the middle of the text string, rather than first as I am used to.
Short of turning ALL my drawings 90 deg, which will screw me up a lot (mainly with the comp axis orientations); is there any way of flipping the Red/Green orientation?

Is there a way to show ONLY the X axis (or Y) in the tag, and not the Y or Z values?

Is there a way to label each tag as it is created, perhaps by simply typing to the VCB the label? Your CofG Ruby picks up the component name. Perhaps you could label the coord tag with that comp name, IF a point on the comp is tagged.

There's more, but later. I need to play a lot more.

Tig Re: Coords....

It seems to do what I need, but I have a few questions about some of the dialogs, which I will post in Coords post.

All I need to say here is, Please think about combining the XYZ coords part with the CofGravity Ruby

I would think that the hard part of coding has been done, and all you really need do is an integration and dialog box changes. I know it is not a trivial task, but a lot of the hard work has been done.

Looks like it should work for me.
I'll try it later today or tomorrow and report back here.