topic Re: Smoothing & masking codes in Libraries & objects

Smoothing & masking codes

derekjackson — Fri, 11 Feb 2011 09:52:54 GMT

Hi,
having an issue with masking codes to get a prism to smooth on the right faces.

Trying to make something like this: http://www.intrad.com/product97372/rcr-125.aspx

It's a shape with 3 main curves on the visible side. I want the object to be smoothed, except at the two creases where the curves meet (as indicated by the red lines in the screengrab).

Alternating between masking codes of 15 and 79 seems to either fully smooth or fully facet the whole object. Is there anyway to specify exactly which edges are smoothed? Changing the 4001s or 900s doesn't seem to affect it.

Code for facetted version:

	PRISM_      14,      rail_length,  
		0.045, -0.04811539936889,      15, 
		0.04144274961775, -0.03895038973231,    900, 
		0, 115.4793648758,   4001, 
		0.04818609361501, -0.03179645769075,      15, 
		0.06574793327563, -0.02074811205036,    900, 
		0, -211.6808401911,   4001, 
		0.0864952753737, -0.02056936776373,      15, 
		-0.005905922275061, -0.06111603154502,    900, 
		0, -47.88603034617,   4001, 
		0.08613703059829, -0.1024694848116,      15, 
		0.06558004796178, -0.1043565827946,    900, 
		0, -180.7544340626,   4001, 
		0.045, -0.1059728438522,      15, 
		0.045, -0.04811539936889,      -1

Code for smoothed version:

	PRISM_      14,      rail_length,  
		0.045, -0.04811539936889,      79, 
		0.04144274961775, -0.03895038973231,    900, 
		0, 115.4793648758,   4001, 
		0.04818609361501, -0.03179645769075,      79, 
		0.06574793327563, -0.02074811205036,    900, 
		0, -211.6808401911,   4001, 
		0.0864952753737, -0.02056936776373,      79, 
		-0.005905922275061, -0.06111603154502,    900, 
		0, -47.88603034617,   4001, 
		0.08613703059829, -0.1024694848116,      79, 
		0.06558004796178, -0.1043565827946,    900, 
		0, -180.7544340626,   4001, 
		0.045, -0.1059728438522,      79, 
		0.045, -0.04811539936889,      -1

Any suggestions, or am I asking the impossible? A last resort is to add in an extra 'straight' face between the curves, but that increases to polycount so I'd rather not...

Re: Smoothing & masking codes

Dwight — Fri, 11 Feb 2011 10:48:16 GMT

This isn't great, but it does differentiate the surfaces.

Re: Smoothing & masking codes

David Maudlin — Fri, 11 Feb 2011 13:28:44 GMT

derek:

You will need to add two more planes for the straight faces (use status code 15), the code you have (which looks like it was generated by ArchiCAD) is all center points (900) and arcs (4001), with a few start points (79 or 15). I wouldn't worry about the few extra polygons, as under the standard resolution (36) your shape is generating more than 50 faces as is. If you want to decrease the polygon count, look at simplifying the back of the rail which shouldn't be seen in 3D anyway (unless you need this for accurate sections at a large scale).

You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.

David

Re: Smoothing & masking codes

derekjackson — Fri, 11 Feb 2011 14:07:16 GMT

Excellent, thanks!

Derek

Re: Smoothing & masking codes

Anonymous — Fri, 11 Feb 2011 15:34:53 GMT

Is there a reason you need to use a library part and not a complex profile for this?

Re: Smoothing & masking codes

derekjackson — Fri, 11 Feb 2011 15:46:02 GMT

That's been the source of massive debate in the office. We're gojng with objects so we can have several profiles saved within one object, along with options to turn corners on and off.

Re: Smoothing & masking codes

Anonymous — Fri, 11 Feb 2011 18:21:28 GMT

derekjackson wrote:
That's been the source of massive debate in the office. We're gojng with objects so we can have several profiles saved within one object, along with options to turn corners on and off.

It does make sense to use library parts if you need more advanced functions, but in this case you may want to go to named variables and hand coded profiles instead of the automatically generated coordinates.

It's not as hard as you might think. What I do is just initialize the variables for each node something like this:

x1    = 0.0
x2    = 0.1
x3    = 0.2

y1    = 0.0
y2    = 0.2
y3    = 0.4

Prism_ 6, length,
    x1, y1, 15,
    x2, y1, 79,
    x3, y2, 1079,
    x2, y3, 1079,
    x1, y3, 15,
    x1, y1, -1

Re: Smoothing & masking codes

Anonymous — Fri, 11 Feb 2011 20:48:06 GMT

David is right, GDL can not handle a rough edge between two curved surfaces.
You have to create a small gap between them, with a different status code (15).

Some exceptions, status code 128 for TUBE, TUBEA (AC12), and REVOLVE (AC13),
allow to get rid of these additional points (and polygons), for cross section profile.

This is a basic feature for any decent CAD/BIM software.
Unfortunatly, progress are slow.

	toler 0.0002

	put  0.0450,   -0.0481, 15, 
		 0.0451,   -0.0481, 79, 
		 0.0416,   -0.0389, 900,  
		 0.0493,   -0.0329, 3000+79,
		 0.0653,   -0.0203, 900, 
		 0.0653,    0.0000, 3000+79,    
		 0.0854,   -0.0239, 3000+79,  
		 0.0853,   -0.0240, 15,    ! rough    
		 0.0854,   -0.0241, 79, 
		 0.0139,   -0.0625, 900, 
		 0.0854,   -0.1009, 3000+79,   
		 0.0853,   -0.1010, 15,    ! rough        
		 0.0854,   -0.1011, 79,
		 0.0653,   -0.1047, 900, 
		 0.0653,   -0.1250, 3000+79,  
		 0.0450,   -0.1047, 3000+79,
		 0.0450,   -0.0482, 79,
		 0.0450,   -0.0481, -1

	rotx 90
	prism_  nsp/3, rail_length, get(nsp)
	del 1

Re: Smoothing & masking codes

Anonymous — Wed, 24 Dec 2014 08:10:48 GMT

I have met a problem with GDL.I have downloaded a 3D toilet part from a manufacturer in 3D DXF format.
The part opens and inserts into the drawings fine. I would like to get control of the facets or mesh created that make up the shape of the toilet to turn off the visible facets and only show the object profile in plan and elevation. Has anyone had success in bringing in complex mesh objects and simplifying their appearance for plan views and interior elevations?Thanks.generate code128 in vb.netgenerate code128 in .net

Re: Smoothing & masking codes

Eduardo Rolon — Wed, 24 Dec 2014 12:40:46 GMT

Typical procedure:
• Import the object
• Convert to morph and follow the instructions here: http://helpcenter.graphisoft.com/tips/removing-triangulation-from-imported-sketchup-cinema-4d-and-3d-studio-objects/
• Save as object