Hi gang, I need your help. In Carrara 5.1 Pro, there is an animal called the Gordon surface. After reading the “simple instructions” on how to create this puppy, I tried my hand at creating one. Of course it was a miserable failure.

 

Could someone give me an example and instructions on how to do it? 

 

Need same help with Coons Surface: Thanks in advance---Jan

Not enough info in the Help manual?

Brian

For coons it is tough.  The four "curves" need to have the same number of points as the curves on the opposite side of the "square".  And yes, the end points of each curve have to touch each other.

Thanks guys.

Got Coons Surface working--problem for that one was what appeared to be touching wasn't (even in left, top and front views).  Attaching a link between the curves ensured the connects
and it worked.  Now to figure out a useful purpose for it that can't be done better in other modes.

Gordon Surface is still a problem-so far simply doesn't work--created three simple 2d square planes.  Added four profiles, two top and two bottom connected to respective points on all three squares.  --went into the Gordon Surface control, but couldn't properly verify the selection of the  three squares or profiles-did change from red to blue, but no other activity.  Jan

Just a little clarification, 

1. Coons surface - there doesn't actually need to be the same number of drawn/clicked points per side when drawing the guidelines. When you complete the last line selection with the Coons tool, Carrara automatically adds extra points to create a quality grid structure. This is true whether using the interpolated line tool or the simple polyline tool.

2. Gordon Surfaces - like the Coons shape, connecting longitude and latitude lines MUST connect. The only way you can do that is by holding the shift key down while clicking the line tool on a point. Close isn't good enough. Even if one point is not connected, the Gordon function will fail.

The Coons tool is excellent for hoods of cars, airplane fuselages, wings and more - especially when creating them from plan views.

The Gordon tool is great for asymmetrical full shapes like boat hulls and shapes that have multiple compound curves. The image is from a project where the Gordon tool was used for a boat hull.

Hope this helps.

Mark

 Here's another view. The hull below the deck line is a single Gordon mesh. The hull profiles were created from historic plans in the vertex room. Then it was just a simple Gordon operation which results in a very nice quad mesh object.

Forgot to mention that you can use the Weld tool in the vertex room if need to get the latitude and longitude lines to connect. For more complex cross sections like in this boat, I welded the cross sections to the midline.

Hi Mark, thanks for your input.  I must be making a very simple mistake-welded the heck out of the connecting points, even moved them to see if the cross sections moved to and they did as shown.  The following screen shot is as far as I got.  This is after I activated the Gordon Surface tool and clicked on each surface (while holding down the shift key), Got the selection of the verticals came up in red. However after verification (depressing the Enter key), every thing returned to this -- Jan

 Ahhh, only use lines, no filled polys.

Thanks Mark, only used lines-still not working.  In fact, after going into Gordon Surface, some of my drop down menus sometime fail to open like file and edit.  First the primary one

After selecting Gordon Surface, clicking on the lines (after selecting the edge function), doesn't change color--Now if I select that large MOVE arrow, then the lines change to red and holding down the shift key can hilight all the horizontal edges and "validating" the group when done, then selecting the vertical lines and "validating" when done and clicking again-nothing-but I can fill the cube beautifully.  Now, what am I doing wrong.

Is it possible that the Gordon function is deactivated if I click on the move function or anything else--if I don't click on anything but the lines, nothing happens either.

The Coons Surface by the way works great, in fact after welding all the intersecting points, when I click on the Coons Surface function, it fills in great.

The latter problem, I simply close down Carrara and bring it up again-and open the save .car file--

Just wondering if the Gordon Surface function is too RAM intensive to work with 500MB of RAM.  Jan  

 Hmmm, I'd try redrawing the shapes. I haven't encountered the issue you mention. If you simply emptied the polys, that might not be enough.

Hi Mark, no I  did everything from scratch again using the polyline function.  I thought that perhaps duplicating the first square caused the problem so I drew each one individually and moved the two so that one was above the other, then drew other polylines vertically to connect with their respective points (welding each one of the corners)  then activating the Gordon Surface and clicked on a horizontal edge (nothing), clicked on a point (nothing) clicked on a vertical line, changed color, but nothing afterwards (at the same time my file, edit drop down menus failed to open-could go to my assembly window.  I'm beginning to think that there is a bug in the Gordon function since it freezes other controls.  Jan

I just created the shape you're trying and it worked here.

Are you drawing your square with the Rectangle line tool or the Plane or Polygon tool? Only use the line drawing tools. The Plane and Polygon tools will not work for Gordon implementation.

Also, be sure to exactly follow the prompts that are shown in the Property tray after you select the Gordon too. They don't mention anything about points and you said you were clicking on those too. ;-)

Hi Mark, first thanks for your patience.
 
I used the poly line tool to create the vertical and horizontal "curves" -- When the instructions state select the latitude curves, to me that means click on all the horizontal lines in turn.  When you run out of horizontal lines, depress the Enter key to stop.  Repeat with the vertical lines and see the Gordon surface generate eg in this case a solid cube. 

I only departed from the instructions when they didn't work.  Jan

 Ok, another basic question to make sure that I'm not over looking something. When you draw your polylines, are you holding down the Shift key on your keyboard as you draw from point to point on the shapes?

Hi Mark, tried it both ways --when I held down the shift key, I couldn't form the line so the answer is no.  I just start it and when I get the line to where I want it, I click on the Enter key to stop.  Jan