[Simon Lucas]

Hi Kouraib

thank-you – that is a good working solution. If you have time to find the cause I would be interested, too.

Regards

Simon

[Simon Lucas]

Looked through an xpresso in detail book that I remembered I had, I started to realise that this is most likely a Python task. I will direct my attention to some experiments in generating objects and setting their parameters with Python, that I played with some time go.

[Simon Lucas]

Thank-you for showing us your technique. Very interesting method. I think perhaps the amount of adjustment by eye is probably equal to what I am doing with look-at-camera tag and nudging the spline inside the null. I went for that latter method yesterday for my final version, and it worked quite smoothly that time.

I will certainly play with your technique and perhaps try it for next one though. Thank-you for showing it.

[Simon Lucas]

After some more experiments, I think I understand this better.

One of the important things is that if the object is off-axis (on any of the 3), then the resulting exported outline spine will not be in alignment once re-imported. It will also be flipped 180 along the x axis – which in itself is easy to fix.

The solution I have found is to add a cube to the scene with coordinate 0,0,0. The outline of this cube and the object of interest should be combined into a single object once imported. Then it should be placed in a Null object, to which the look-at-camera TAG is applied. Then the nested spline object is flipped, scaled* and lined-up by eye, using the cube as a guide. Cube part of the spline can be deleted once aligned.

*I have not quite worked out the scale factor, as it seemed to change from one project to the next. But this can be worked out by trial and error, and an appropriate cm. scale applied during spline import.

[Simon Lucas]

Using the Look-at-camera TAG goes some way to a solution, but the object is flipped 180 degrees, and even when corrected it still has to be aligned by eye.

Example that makes clear the 180 degree flipping

Cube-With-Protrusion-1.zip 88 KB Zip - Click to view

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[Simon Lucas]

It works thank-you!

A couple of points for anyone else trying this.

a. Exclude the turbulance field from the moSpline – otherwise the destination spline (the on neing used in the field forces will go crazy. I excluded all the forces for good measure.

b. The MoSpline appears to be destructive, as the original spline cannot be restored even after removing the MoSpline. So I have a destination spline and two splines used as alternative sources, as desired.

See the example I attach.

MoSpline-with-partical-follow.c4d 285 KB Cinema 4D project files - Click to view

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[Simon Lucas]

Hi Kouraib

that’s amazing. I just tried a simple example, and now will try it in my full set-up.

Thank-you!

[Simon Lucas]

Hi Kouraib

thank-you. I think I was typing up my post as you posted yours.

I’ve not used MoSpline and not totally sure what you did there. Did you turn the first Spline into the second spline Spline.1 using MoSpline?

I’m all for easier solutions! I need to look at MoSpline.

[Simon Lucas]

I have worked out what is going on here. There is a problem using structure manager to copy and paste spline points from one spline object to another spline object fails under a specific circumstance. A circumstance I did not identify in my opening post. This applies to versions r25 and 2023. And there is a work-around.

The PROBLEM is to do with using edge-to-spline created splines.:

1. Create a sphere. Make it editable with ‘c’. Select an edge loop on the sphere. Use ‘edge-to-spline’. Throw away the sphere an keep the resulting ‘sphere.spline’ object.

2. Create an empty spline.

3. Open the Structure Manager.

4. Select sphere.spline and use select all in Structure Manager. Copy the list of selected points.

5. Select the empty spline. Paste. Either nothing happens or c4d beach-balls. Certainly the beach-balling will happen on a second attempt, I think.

SOLUTION

Do everything as before but with the following changes

3. Create a square. Use ‘c’ to turn it into a Spline object.

5. Select the square-now-spline object. Paste. Then delete the square’s points.

—

In my case I have to make sure I start with square-turned-to-spline objects when setting up my original multiple Force Object templates.

[Simon Lucas]

Thank-you. I think that I’ve worked out that Strength and Contrast have the most effect.