Curved Segment using GDL Primitive Elements

[Nader Belal]

Hi everyone,

Can someone explain me how to create curved arcs and surfaces using VERT, VERT{2}, TEVE, EDGE, & PGON ??

I tried searching for an example to follow, but I couldn't find any.

[runxel]

I don't think that is possible.

How do you got the idea it could be done? With those commands you basically model single polygons. And polygons can never be bend...

[Nader Belal]

Well I just have found out how ... you can, but it a time consuming process 

[Nader Belal]

Just give me a shout for tomorrow or after tomorrow and I will give you the steps to do it

[runxel]

Okay, great, always love to discover new methods!

I'm really eager to know how you achieve this.

[leceta]

same here, I still need to see this with my eyes. A simple example should be enough to show the implementation... How are you defining curves using vertices, edges and polygons (and apparently not being able to use status codes on corresponding commands)? Very curious...

[Nader Belal]

Alright, I will make two posts and share it here

[Peter Baksa]

All GDL commands will get translated to these primitives by AC. Curved surfaces just have many small polygons.

Here is some help for using TEVE: http://gdl.graphisoft.com/gdl-style-guide/script-type-dependent-recommendations

I'd recommend using BPRISM_ and COOR{3}  for a curved panel btw.

[leceta]

Thanks Peter, I understand this, its like many other platforms, rhino for example, where one can define nurbs surfaces (mathematically continuous) but still are represented (and only represented) as meshes (discrete representations). Further operations on that surface still are on the nurbs, though.
My surprise was in relation to the aim of defining "curves" or "curved surfaces" through a discrete system, which "is" (or "seems", afaik) an oxymoron.
In a private conversation, if I understood him correctly, Nader was trying to obtain a smooth representation of a discrete surface, which is all about shaders (well, and in the case of GDL applying the appropriate status code to de edges/polygons.

[SenecaDesignLLC]

My poly tube calculates the positioning of the materials along curve sections for this exact purpose in terms of like a wood curved railing so that you can get a consistent wood grain all the way up the curve One of the things I hate about ArchiCADs railing tool

[SenecaDesignLLC]

https://youtu.be/3WW5X7Q8FIc

[leceta]

thank for the video seneca, really great job!
But for the sake of clarity in relation to the post, let me comment that your particular example is more related to texture UV mapping (TEVE, I suppose) than shading (which happens to be related to vertex normals). Correct me if I'm wrong.

bests, Aitor

[Nader Belal]

Buy the way, I'm half way through

[SenecaDesignLLC]

Curious as to why you would want to use the primitives?

[Nader Belal]

Because sometimes, and depending of the elements' complexity/resource usage, it can be more cost effective to just model the desired element using Primitives.

In my actual case, since GDL lacks morphing or mapping (don't know the correct term) a regular cubic model to a similar curvilinear shape, and scripting that will be more be more time consuming with lower quality result.

That besides, the god damned standard GDL manual doesn't have an example for that.

[SenecaDesignLLC]

Curious, what are you modeling?

[Nader Belal]

Curved cabinet door panel

[SenecaDesignLLC]

I just use tubes and map the surface around the segments I guess I felt like primitives would be more work.

[Nader Belal]

Usually I would do that, but the overhead is unacceptable

[Nader Belal]

By the way, I´m half way through