# Cylinder through curved deck

DELFTship forum Hull modeling Cylinder through curved deck

• Author
Posts
• #44722
RuudN
Participant

Hi,

For making a kayak-deck hatch I have used the Cylinder-tool to make a cone that goes through a curved deck. I want to have the deck faces to stop at the intersection-line with the cone. From the Point menu the intersect feature gives me extra control points in the deck but I have not figured out how I can remove the deck inside the cone properly. In every way I have tried there remain small parts of deck inside the cone.

In the pictures you can see the deck (green) with the cone before using the Intersect-feature.

Is there a way to get the deck inside the cone removed up to the intersection with that cone?

###### Attachments:
• #44727
Marven
Keymaster

The easiest way would be to remove all faces of the deck which are inside or (partially) overlapping the cylinder. Then close the hole in the deck by stitching new faces between the edge of the hole and the edge of the cylinder

• #44728
RuudN
Participant

Thank you, it solved part of the problem. Probably I will have to subdivide the control net and reposition the cylinder in order not to miss control points where I need them to select edges.

• #44729
Terrance Egolf
Participant

RuudN,

The situation you are trying to model in DELFTship can be a little tricky. Trying to create a circular hole located in a surface at the centerline will fail if only the left half the surface is modeled. This is due to the underlying mathematics used to model curved edges in the program. The curve at the centerline control points will always be crimped.

I suggest that you first model both sides of the deck on a single layer. You can use the Mirror tool in the Transform menu group under the Tools tab to easily create the right side of the deck. Be sure to check the “Connect to existing points” option with zero offset “distance.” (Also, verify that you can remove the crease in the edge at the centerline after the Mirror operation to verify that both sides are truly one surface. The Mirror operation can sometimes be buggy.)

Next, rather than using the Subdivide control net feature in the program, which increases the number of all the faces in the model, I suggest just recreating the conical structure of the hatch using more faces to better define the intersection of the hole with the deck.

Then create the intersection between the deck and hatch layers, inserting the points in the hatch layer. This operation will create a smooth crease edge in the hatch layer that closely follows the deck curve.

Delete the portions of the hatch faces that lie below the deck surface.

Delete the faces in the deck that intersect the hatch.

Manually rebuild the deck faces in way of the hatch by using the Add face feature in theĀ Face menu group by connecting points between the deck and hatch with edges. (See an example from my model, attached.)

I think this approach will solve your problem.

Terry

###### Attachments:
• #44733
RuudN
Participant

Hi Terry,

Thank you for the help, really appreciate that. I will give it a go soon.

Regards, Ruud

• #44734
Terrance Egolf
Participant

One thing I forgot to mention is that you will probably have to re-establish the crease edge between the hatch skirt and the deck once you are finished rebuilding the deck surface, since the process of adding adjacent faces often uncreases the common edges.

Terry

• #44738
RuudN
Participant

It worked! Thanks again Terry!

###### Attachments:
• #44740
Terrance Egolf
Participant

Great! Looks good!