Basic 2d spline functionality


These may be some of the stupidest musings ever… I’m new to C4D so maybe I’m just not adjusting well. These points/questions all refer to working with splines in 2d, although many of the functions work fine with 3d objects. I’m using ver 8.5

1). Weld vertices of a spline in 2D.

If I have 2 separate lines in one spline (I’ve used connect to join them) and I move the vertices of the end points of each line together so that they are coincident and try to weld them… nothing happens. If I do this in 3d they weld no problem… Maybe I’m using the wrong tool? So how do I join 2 vertices together in 2d?

2). Connect two points together

Similarly if I have 2 or more lines and I want to connect them there seems to be no easy way of doing it. The join segment seems to always join the “first” vertex of one line with the “last” point of the other line.

In nearly every app I’ve used you can join any two points… you just draw to connect point A to B… simple. But C4D decides which points to join for you based on the points sequence. Before you join two points together you need to ensure that they are in the correct sequence and then C4D joins them. Is there a way around this arcane method?

3). Trim lines

If two or more lines cross over each other you can I trim the lines at the point of intersection… simple basic functionality but I can’t see how to do it.
It would be easy to get around if I could do 4 and 5

4). Select a segment of a line

I have the “Edge tool” (Point, Edge & Polygon) selected, but nothing happens… I can’t select an edge. It only works in 3d. The only way I can move a segment is to select the vertices at either end and move them. It would be better if you could select segments as entities in their own right… that way you could perform operations at the segament level.

5). Delete a segment of a spline

I can’t do 4, so I can’t do this either. I can work around this through a combintion of breaking and adding points… but it’s cumbersome and inaccurate.

6). Break or Detach a segment

The “Break” segment is misleading. It does not break the segment… it re-routes the spline so that the point you had selected is avoided. In most 2d and 3d apps “break” implies adding 2 co-incident vertices at a point and opening the spline.

I’d like to be able to detach a segment of a spline.

7). Chamfer a vertex

The chamfer function is in fact a fillet function!
To chamfer a fillet you have to adjust the handles on the two vertices or you could just set the type of spline to linear. I think this may be related to point 4… there does not seem to be the notion of a segment in 2d. If there was each segment could be treated individually, and the chamfered edge could be straight while the rest retain their own curvature.

8). Boolean 2 or more splines ( I think someone wrote a plugin to do this for release 7)

I can’t believe they omitted this. PLEASE, PLEASE, PLEASE add this.

9). Draw primitives.

You can draw a spline… why not a rectangle, circle arc, cube etc. Instead they are created in either the centre of the viewport or axes origin when you click on icon… then you have to adjust its size position etc.

I don’t know if any of yee guys have found any of these to be a problem. I find C4D to be sweet in 3d, but I just can’t get my head around how difficult it is to draw anything but the most basic splines in 2d. Has anybody got any suggestions… are there plugins that have addressed these? Or should I just draw my stuff in 2d elsewhere?

Thanx in advance!


yes splines tools in cinema are woefully inadequate however there are a few things that might help you:

for 1, i’ve never been able to weld spline points at all in cinema, 2d or 3d, closest i can find is join segment, maybe you mean snapping to a point, snapping works pretty good for me, maybe if you do mean snapping you simply haven’t turned snap to 3d mode (in 2.5d it doesn’t move along camera z so it’ll only apparently snap from your current pov once you move the camera it’ll likely not be snapped correctly, 3d actually fully snaps to the element).

for 2, just select the two end points you want to connect, and go Structure->Edit Spline->Join segments, it will now connect the two splines at those two points, you cannot connect mid points together (you can’t even do this in illustrator or freehand afaik, though you could click set first point first then join segment however that owuld ttoaly alter the shape of your spline).

3 there are no trim commands for splines in cinema.

for 4 and 5, select any point of the segment and use Selection->Select Connected, now you have the segment(s) selected that you wanted. just hit delete to remove the segments

6 try structure->edit surface->disconnect

7 for a quick result just chamfer again for 0 length, or with the newly created points selected choose Structure->Edit SPline->Hard interpolation

8 booleans as are all path functions are not there, trim fits into the category of spline/spline interaction, and i agree it should be there

9 agreed, i even have a start of a plugin somewhere designed to deal with this, maybe i should complete it sometime.


Well, mdme_sadie answered the substantive questions. I agree that spline drawing in Cinema is pretty rough. Better to do it in Illustrator, Freehand, Corel, or the like. Most of the spline modeling I used to do in Cinema I now do in Rhino, which has exceptional drawing tools.


Yes please, I’d be the first to buy it.


Thanks mdme_sadie, my mistake/inaccuracy about welding…
You can do it no problem with a 3d object after you’ve made it editable.

Those points all work well, points 2, 6 & 7 will speed me tremendously.

I think you should get back to the plugin if you can… I’d buy that and I’m sure more than a few others would too!


samir used to have a plugin for boole of splines (splinebooler) i think not same issue as discussed…but can’t find it on his site anymore.

there is the splinemizer (point reducer…which is pretty handy)…especially if you don’t have ditools and its a freebie…and spline deformer.

sorry for the detour…but slightly spliney related.


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