Jump to content

Best way to build elliptical ramps that narrow as you move up


jnr

Recommended Posts

So trying to wrap my head around this one. Plan view of two ramps with walls. starts wide and narrows as you move up. This maybe an update to a previous post from 2012 but was not able to follow.  Iso view shows a nurbs as a walking surface which is fine if the wall covers the whole underside, not fine if the ramp is exposed and has to have a thickness. one of my pet peeves is once you get to generic solid, there's no legacy so you can't go back if you need to adjust. Also attached is an iso of the ramps as nurbs, no thickness. 

 

Ideas?

 

59670c0f9cf56_ScreenShot2017-07-13at1_57_22AM.png.fd954ff099c47e3e37c96c11548b1485.png59670da103e74_ScreenShot2017-07-13at2_04_37AM.png.7ae92e21dd0d454c53e966becb9169db.png

Screen Shot 2017-07-13 at 1.57.22 AM.png

Link to comment

bcd: thanks for the response and taking time to think about this.. I'm running on little sleep so I'm not following how I would keep the shape generated in plan. Seems like scaling factor is yet another exercise of trial and error to get the shape one wants. EAP only allows a single nurbs so I'm not sure how to maintain the shape you want. EAP good idea for the walls/railings. What am I missing?

Link to comment

You're not missing anything.

My question would be what is defining the plan in the first place? Perhaps you need to approximate it using 3d methods and then substitute the plan with the actual plan derived from the 3d model.

 

 

Link to comment

I'm tearing into this today and will try to post later. Other fish in the frying pan, (layer transparencies with referenced files, camera match hell, water textures etc.).  Yeah at this juncture, its 3d approximation. 

Link to comment
10 hours ago, jnr said:

Ideas?

 

Although not a modelling tip, I made a huge ramp like this a few years ago based on client drawings.

The main issue with the as-built version was the change in pitch on the tighter radii... Along the long edges it pitched very gently, and at the tighter rads it pitched very steeply, especially on the inside corner.

The model prototype demonstrated that the internal pitch of the tight rad was far too steep, with only 1 in 12 allowed in the EU... so we ended up doing flat "landings" on the tighter ends, and then only pitched up the longer sides. This also had the side effect of offering a good surface to get on and get off... So....

 

Looking at your design the ellipse is split in two, with a gantry between the halves. So, might it be an approach to extrude your surface in plan, and then simply rotate it a little in elevation to match the environment? That way you don't get the tightening on the corners, and it's a lot easier to model and much cheaper in the final construction too.

 

  • Like 1
Link to comment

R:

Thanks for the tip, and good point about the tight radius. This is in Prague and funded by the EU, so its game on. I think if I build one side in two halves with a landing as you suggest at the tight radius, I can flip the ramp over and mirror it for the other side. Its subject to complete flood immersion so it will all have to be robust cast in place concrete.  I can't really rotate in environment as the model is propagated in all sorts of camera match, section and plan views. Gotta suck it up and build it in 3D.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...