Helix Along Curve - Is not working on curves?!

Dave R · 11 Dec 2023, 16:24

Scaled up the path, and also the radius dimensions to match.

Share the .skp file so we can see what you're working with.

What version of SketchUp? What operating system? Please complete your forum profile.

Richard-Leeds-UK · 11 Dec 2023, 16:42

@dave r said:

@richard-leeds-uk said:

Scaled up the path, and also the radius dimensions to match.

Share the .skp file so we can see what you're working with.

What version of SketchUp? What operating system? Please complete your forum profile.

Thanks Dave have attached the .skp file and updated profile.

HELIX CURVE ERROR.skp

Dave R · 11 Dec 2023, 16:54

Does this look like what you want?

First I welded the edges so it's easier to select the entire path. Then I created a component which I copied. I scaled the copy up by a factor of 1000. In the UI for Helix Along Curve I entered the values as you showed (although I used the recommended value for Adherence).

The issue in your model is the tiny size as Box alluded to. Scaling up gets around that. There's no error in the extension.

Here's the file with the large copy. Select that copy and delete it. Then hit Zoom Extents to see the orignal one.
HELIX CURVE NO ERROR.skp

Richard-Leeds-UK · 11 Dec 2023, 17:07

@dave r said:

Does this look like what you want?
[attachment=1:2nb17x6r]Screenshot - 12_11_2023 , 10_47_59 AM.png[/attachment:2nb17x6r]

First I welded the edges so it's easier to select the entire path. Then I created a component which I copied. I scaled the copy up by a factor of 1000. In the UI for Helix Along Curve I entered the values as you showed (although I used the recommended value for Adherence).

The issue in your model is the tiny size as Box alluded to. Scaling up gets around that. There's no error in the extension.

Here's the file with the large copy. Select that copy and delete it. Then hit Zoom Extents to see the orignal one.
[attachment=0:2nb17x6r]HELIX CURVE NO ERROR.skp[/attachment:2nb17x6r]

Brill, thanks Dave R for your help.

I still can't understand why the helix generates on a straight path of the same dimensions but not the curve (even at 100x scale) - but never mind!

Thanks again - everyone!

Dave R · 11 Dec 2023, 17:25

The edge segments were still too short at that size. How will you use this helix now that you have it? I'm wondering if you even need it to be so small.

Box · 11 Dec 2023, 22:10

@richard-leeds-uk said:

I still can't understand why the helix generates on a straight path of the same dimensions but not the curve (even at 100x scale)

The tiny face issue isn't actually about the faces, it is the spacial relationship of the vertices of the edges. When they get very close together Sketchup decides they are suppose to be in the same place and will just ignore them. An over simplification but basically the problem.
So while the helix is following a straight path the vertices are just far enough apart to work but as they go around the arc their spacial orientation changes moving them closer together causing them to fail.
It is very common with a simple follow me to have it work along a straight edge but then fail around a radius corner, Or a small sphere will end up with a hole in the top and bottom. In the sphere the edge lengths should be long enough for it to work but it is the distance the vertices are apart on the z axis that causes the problem.

Richard-Leeds-UK · 12 Dec 2023, 16:34

@dave r said:

The edge segments were still too short at that size. How will you use this helix now that you have it? I'm wondering if you even need it to be so small.

I was modelling a kitchen tap for CGI on our website, it was drawn at 1:1.

One of the final renders attached

Richard-Leeds-UK · 12 Dec 2023, 16:35

@box said:

@richard-leeds-uk said:

I still can't understand why the helix generates on a straight path of the same dimensions but not the curve (even at 100x scale)

The tiny face issue isn't actually about the faces, it is the spacial relationship of the vertices of the edges. When they get very close together Sketchup decides they are suppose to be in the same place and will just ignore them. An over simplification but basically the problem.
So while the helix is following a straight path the vertices are just far enough apart to work but as they go around the arc their spacial orientation changes moving them closer together causing them to fail.
It is very common with a simple follow me to have it work along a straight edge but then fail around a radius corner, Or a small sphere will end up with a hole in the top and bottom. In the sphere the edge lengths should be long enough for it to work but it is the distance the vertices are apart on the z axis that causes the problem.

Thanks, Box for the explanation - most appreciated & useful

ntxdave · 12 Dec 2023, 16:43

Your final result looks good to me.

Richard-Leeds-UK · 12 Dec 2023, 17:58

@dave r said:

@richard-leeds-uk said:

it was drawn at 1:1.

If it's for a render like you show, it wouldn't have to be 1:1.

Yes I appreciate that - it's a habit i'm in drawing in millimetres for many years - I should totally set my units to metres and pretend they are MMs when using sketchup.

Lots of my work however is necessary at 1:1 for transferring to layout etc.

Dave R · 12 Dec 2023, 17:12

@richard-leeds-uk said:

it was drawn at 1:1.

If it's for a render like you show, it wouldn't have to be 1:1.

Nice render, by the way.

These are just quickie renders from a model I did. In reality the base of the key is 3 in. wide by 4.75 in. long. In my model it's 3 meters by 4.75 meters so that I could create the tiny detail like the screw threads, spring, and raised text without risking loss of faces.

ntxdave · 12 Dec 2023, 17:21

Like you model too Dave R.