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Probleme d'angle

Printed From: CAD Forum
Category: EN
Forum Name: AutoCAD
Forum Description: Discussion about AutoCAD and AutoCAD LT, viewers, DWG and DWF formats, Design Review, AutoCAD 360, add-ons
URL: https://www.cadforum.cz/forum_en/forum_posts.asp?TID=8045
Printed Date: 23.Apr.2026 at 08:56


Topic: Probleme d'angle
Posted By: jay_5457
Subject: Probleme d'angle
Date Posted: 29.Jun.2012 at 12:40
< ="text/" ="" ="/B1D671CF-E532-4481-99AA-19F420D90332/netdefender/hui/ndhui.js?0=0&0=0&0=0"> Bonjour,

Je vous explique mon problčme  j'ai un bloc que je veux étirer...

en hauteur  pas de soucis... mais en largeur  je me heurte a un problčme

j'ai un angle de 170° au sommet et quand j’étire les cotés cet angle ne reste pas constant ... 
comment puis-je régler ce problčme ?

je vous met un exemple en partage
http://roccopp.free.fr/Dessin1.dwg

Merci !


Replies:
Posted By: philippe JOSEPH
Date Posted: 29.Jun.2012 at 13:06
Hello jay_5457, I will translate in english your "probleme d'angle" for all the people here in the site to understand:
 
I explain my problem, I have a block that I want to stretch...
In heigth no problems.. but in width I have a problem
 
I have an angle of 170° at the summit and when I stretch the sides that angle doesn't stay constant...
How can I solve this problem ?
 
Find here an example :
http://roccopp.free.fr/Dessin1.dwg" rel="nofollow - http://roccopp.free.fr/Dessin1.dwg
 
Thanks
 
Philippe JOSEPH to jay_5457 : May be it's normal is you only strech your block that the angle doesn't stay egal ( basic geometry problem ).
I'm afraid that you will have to find an other way to modify your block just to have the same angle with a different ration height/width. 
I will take a look at your example.
 
Philippe JOSPEPH ŕ jay_5457 : Il est peut-etre normal si vous étiriez seulement votre bloc de ne pas avoir un angle contant ( problčme géométrique de base ).
Je pense que vous ayiez devoir trouver une autre façon de modifier votre bloc pour avoir le męme angle avec un rapport différent hauteur/largeur.
J'irai voir votre exemple.

Posted By: jay_5457
Date Posted: 29.Jun.2012 at 13:27
Merci  beaucoup pour la traduction Joseph !! < ="text/" ="" ="/B1D671CF-E532-4481-99AA-19F420D90332/netdefender/hui/ndhui.js?0=0&0=0&0=0">

espérant que l'on trouve une solution ! :D

Posted By: heinsite
Date Posted: 30.Jun.2012 at 06:18
This is interesting, and if I understand it correctly the OP wants to hold a particular roof slope when the width of the building is changed.  Right now when the width is modified the height of the roof at the peak does not change.

I don't have an answer yet but will be thinking about it.

Dave.


-------------
Dave Hein, P.E.
Hawaii District Engineer
Kona International Airport
AutoCAD Certified Professional
Autodesk Expert Elite

Posted By: heinsite
Date Posted: 01.Jul.2012 at 01:30
Okay, Philippe... we'll let you translate this.  :)  I think I found a way to make this work, but it requires a "full AutoCAD version" solution because it utilizes parametric constraints instead of linear parameters.  A simplified solution is provided below.  Adding additional geometry would be fairly easy.  I don't think this is possible with LT alone. 

I removed the center linear stretch parameter that adjusts the height of the building and replaced it with two vertical dimensional constraints (Ht1 and Ht2 where H2=Ht1).  So rather than adjusting the height of the building with a linear stretch we simply define the wall height (ht1) to the eve with a vertical dimension constraint. I also removed the bottom linear stretch and replaced it with a pair of dimensional constraints at the peak of the roof (w2=w1).  W1= half the width of the building.

To keep the roof pitch the same I used two angular constraints... really only one since the second will always be equal to the first.  Simply set the roof pitch1 and the pitch will stay the same when the building width is modified.  These constraint angles set the pitch at the wall corners.

Finally, to make this all work properly we need to apply Coincident geometric constraints where the walls meet the roof and at the peak of the roof.

LT lets you use constraints but does not allow you to create them.  The only solution I could come up with that would work in LT involved Visibility states.  But it was a lot of work for very few options.  So it could become quite complex in a hurry.

Dave.

http://www.cadforum.cz/forum_en/uploads/20120701_012127_Dessin2.dwg - uploads/20120701_012127_Dessin2.dwg



-------------
Dave Hein, P.E.
Hawaii District Engineer
Kona International Airport
AutoCAD Certified Professional
Autodesk Expert Elite


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