topic Re: Prism with a smaller base than top... in Libraries & objects

Prism with a smaller base than top...

JGoode — Wed, 12 Dec 2018 12:22:51 GMT

Hello,

I want to make a prism that has curved corners and also a smaller base than top (like a cone).
What is the best way to achieve this?

Thanks

Re: Prism with a smaller base than top...

Barry Kelly — Thu, 13 Dec 2018 02:36:18 GMT

Probably RULED or SWEEP.
But maybe TUBEA.

I have used RULED to make baths and basins where the size changes with height.

Barry.

Re: Prism with a smaller base than top...

Lingwisyer — Thu, 13 Dec 2018 03:22:09 GMT

But how do you make just the corners rounded?

Re: Prism with a smaller base than top...

Barry Kelly — Thu, 13 Dec 2018 04:09:54 GMT

Lingwisyer wrote:
But how do you make just the corners rounded?

For the SWEEP you can do something like this.

SWEEP 13, 2, 0, 2, 1*1 + 2*1 + 4*1 + 16*1 + 32*1 + 64*1,
              -0.025,        -0.05,     1, 
               0.025,        -0.05,     1, 
               0.025,       -0.025,    900, 
                   0,           90,   4000, 
                0.05,        0.025,     1, 
               0.025,        0.025,    900, 
                   0,           90,   4000, 
              -0.025,         0.05,     1, 
              -0.025,        0.025,    900, 
                   0,           90,   4000, 
               -0.05,       -0.025,     1, 
              -0.025,       -0.025,    900, 
                   0,           90,   4000,

				0, 0, 0,
				0, 0, 0.2

With the RULED I think you have to specify many points on the curve (i.e. many straight lines).
I think this is because the nodes of the polygon are listed twice - the first has a status code for visibility and the second has the height - so the mask for curves doesn't work.

I use a gosub routine like this to create the many nodes of a corner.


start_angle = 180
end_angle = 270
x_add = -x_val-x_squ_add
y_add = -y_val-y_squ_add
gosub 100


100:
FOR angle = start_angle to end_angle step 10
PUT x_add+(rad*COS(angle)), y_add+(rad*SIN(angle)), z_status
next angle
RETURN

I have never really used the TUBEA so can't comment on that one.

Barry.

Re: Prism with a smaller base than top...

Lingwisyer — Thu, 13 Dec 2018 05:12:05 GMT

Is it the edges or the corners that need to be curved?