Radius Modify Curve

Hi IStonia,

Looks like the "Radius Modify Curve" function is broken on "Slide" and "Spline Modify". I can only get it to function on "Slide > Tube", but only when the tube is set at certain radius, and then it  offsets in various directions between planer XZ and planer XY.

Could you please check.

Thanks,

It looks ok to me.

You need to watch out the profile spline's pivot position in 'Slide', rendered as two cross lines in red and green. And the related position between Axis Line and Path Curve in 'Spline Modify'.

I don't think the 'Radius Modify Curve' Can work properly in tube option due to the way the circle profile curve is created. You don't have the way to control its pivot position.

You need to watch out the profile spline's pivot position in 'Slide', rendered as two cross lines in red and green.

The profiles pivot is set to its center, which is set to the start of the path. Should it be set somewhere else?

And the related position between Axis Line and Path Curve in 'Spline Modify'.

I have tried just about every possible position, which still makes no effect of the radius of the slide.

Could you please post an example of your splines/setting with the "Radius Modify Curve" functioning?

Thanks,

The profiles pivot is set to its center, which is set to the start of the path. Should it be set somewhere else?

Yes, you need to move the profiles pivot away from the start of the path. Otherwise, any scale times 0 = 0. Normally, you should move the profile spline as whole in object mode, because the transform center has been changed to spline pivot instead of curve geocenter, remember?

I have tried just about every possible position, which still makes no effect of the radius of the slide.

Could you please post an example of your splines/setting with the "Radius Modify Curve" functioning?

Thanks,

I need to restudy the algorithm.

Yes, you need to move the profiles pivot away from the start of the path. Otherwise, any scale times 0 = 0.

We appear to be confusing the profile for the slide with the profile for the Radius modification. I have the profile for the slide at the start of the path.


Never mind. My fault, I now see the errors of my way.

Sorry for my confusion. Senior moment.

Regards,

-Steve

I think it worth my explaining the confusion I had, as it is due to an inconsistency.

For example, with the "Slide"
I can create a 2 point "Path curve", slide along that path, then use "Scale modify" or "Move modify" or "Twist modify" on that "slide" using a modify curve. But, I cannot use a "Radius modify" on that. For the "Radius modify" to work, the path must contain at least 3 points(vertex).

There is probably an underlying reason for that?

It should work. Show me a picture.

I did have it working, but the saved file, after loading to check, the "Radius modify" refuses to work either on a 2 point or even 5 point path.

This appears to be a bit buggy.

-------------

OK, not sure why, but now with me creating new scene/profiles/paths, it is again working.
If I see the problem again, I will e-mail you the file.

Still having problems. It appears the "slide > Radius modify" does not work a lot of the time, but if I save the file, re-load, then most of the time it will then work (too unpredictable).
The "Spline modify > Radius modify" will not function when the path curve as only 2 points(as I already mentioned), it does then work if I use a "Path curve" with more than 2 points, but the resulting mesh can be corrupted, not a lot, but enough to make it unusable.

I will mark the "Radius modify" as buggy, and avoid it.

I can't see why it doesn't work. 'Radius modify' is supposed to work in conjunction with twist value being not zero or it's meaningless. In 'Slide' tool, make sure the path curve start point is not too close to the profile cuve's object pivot. In 'Spline Modify' tool, make sure the path curve point is not tool close to the axis curve's start point. This will provide a position offset value to be modified by the 'Radius modify curve' along the path.

'Radius modify' is supposed to work in conjunction with twist value being not zero or it's meaningless.

I thought (and according to help file) it is the "Twist modifier" that works in conjunction with "Twist" set at non-zero. Why would "Radius modify" be in conjunction with "twist"?

 

In 'Slide' tool, make sure the path curve start point is not too close to the profile cuve's object pivot. In 'Spline Modify' tool, make sure the path curve point is not tool close to the axis curve's start point. This will provide a position offset value to be modified by the 'Radius modify curve' along the path.

You are making me confused. Are you stating that the "Profile"(the curve that will be used for the slide) should not be close to the "path"? In the help file, it states the opposite.

The help file may need to be updated.

Imagine when you swing an object around and along a path and you want to chang the distance between the object and the swing pivot point at the path according to the position of the swing pivot point.

OK, so you are putting forward that the "Radius modify" needs a non-zero distance between the path start and the profiles pivot. That I can understand, and it appears to work. Although I can still get it to work (at times) when the profile is set to path start (zero distance), which is probably what is confusing me about the function.

There is always a computation error in floating number processing. So when you think two points are at the exact loaction, most of the time they aren't. That's why I said make sure they are not too close to each other.

There is always a computation error in floating number processing. So when you think two points are at the exact loaction, most of the time they aren't.

Do you not round to a specific number of decimal places to force an absolute zero?

That's why I said make sure they are not too close to each other.

IMHO, It would be wise to change the help file to reflect that.

Now I have better understanding of how it should function, I will experiment to see what results I can get.