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CAD Forums => CAD General => The Third Dimension => Topic started by: pmvliet on September 10, 2008, 09:49:34 PM

Title: 2d Projection to 3d surface
Post by: pmvliet on September 10, 2008, 09:49:34 PM

Been out of the 3D Autocad realm for a while and I can't remember is Autocad can do this or not.
I don't think it did this in the past, but how about now? I briefly looked through '07, but can't
find anything.

Anyone have a lisp routine?

Situation is I have a flat reflected ceiling which represents a sloping ceiling. I'd like to project
the ceiling grid onto a surface representing the actual ceiling grid. Not sure if this is doable or not.

Any thoughts,

Thanks,
Pieter

Title: Re: 2d Projection to 3d surface
Post by: jnieman on September 10, 2008, 10:13:36 PM

you mean you have a ceiling grid layout that is true-size and true-shape?   Mean it's ... un-bent or un-folded?

If so, then yes, there's no stock way to transfer that onto a curved surface in Autocad.

If you have a reflected ceiling plan that is a true plan, meaning it's not true size, and has distortion due to looking at a slanted surface in plan view... then there's hope.

Let me know which case is true and if the latter is so... how do you want it transfered onto the 3d ceiling?  What type of object is the ceiling model?

If it's the first case, then yea, you'd need something automated and I don't even know how the heck anyone would even START progarmming that... if you find that, I'd -love- to see the principles of that routine... that'd be some awesome programmatic trig.

Title: Re: 2d Projection to 3d surface
Post by: MickD on September 10, 2008, 11:00:42 PM

I'm just wondering if solprof could do it but I don't think it lets 2d lines through the hlr engine, I could do this if there was a real need for it but not for a one/two off job.

edit: this would only work with flat surfaces to take the projection, curved is just too out there :)

You could try projecting the line work using point filters and some set up lines etc. A bit hard to explain but it can be done.

Title: Re: 2d Projection to 3d surface
Post by: pmvliet on September 10, 2008, 11:09:42 PM

Josh,

I have a 2d ceiling plan which represents a ceiling that slopes at 1.7xxx degree's. the slope is constant, so
it is a flat surface, just sloped in one direction. The ceiling plan is not distorted. So, it's a 2' grid ceiling
with a 6" grid every 12'.

I was just looking for an easy way to at project this up. I guess it's not that critical, but
I was just digging around to see if there was a slick way to do this...

Thanks

Title: Re: 2d Projection to 3d surface
Post by: jnieman on September 11, 2008, 12:24:04 AM

Oh a constant slope?  awesome!  that's MUCH easier than I was thinking.

However, (might be my fault after a few beers.. or 6 packs) but I'm not 100% sure about what you are starting with and what you want to end up with.

Maybe post a file, and I can show a kind of step-by-step of how _I_ would do it (and others can probably critique too) and I'd be more than happy to apply whatever knowledge I have to your application.

Title: Re: 2d Projection to 3d surface
Post by: pmvliet on September 11, 2008, 01:58:34 AM

since it's 2am and I just got done working, I'll post the file later on Thursday...

Thanks,
pieter

Title: Re: 2d Projection to 3d surface
Post by: pmvliet on September 11, 2008, 02:08:47 PM

Here is a file.
There is a yellow 3d face that goes up which is where the ceiling
is and the slope that it carries.

I played with this a little and realized that it would actually be easier
to just recreate this. It's not that complicated. standard 2x2 grid
with a 6" gap ever 6th tile.

The tricky thing is that, I really don't have enough information
to know where the grid was actually starting. That's another story.

Anyways, guess I'm good for now, but might be something to think about.

Thanks,
Pieter