Help building roof (and how to prevent corrupt walls)

[JBme]

Hi,
I'm trying to build a roof for the first time and I'm having trouble. I have a building with 4 floors then a narrow tower
coming up from the 4th floor. I'm trying to put a roof on the 4th floor. I have selected the 4th floor, and the roof by perimeter tool, then
selected the roof type. The cursor changes to a little roof picture inside the 4th floor walls and I click there. The program does nothing - no roof appears.
The 4th floor has an outer wall that is curved, but I don't know if that is stopping it build a roof. I tried to do a roof by picking points and selected a rectangle
that overlapped the curved wall, but each time I have tried that, the program stops responding and eventually I have to kill it as it never comes back to
life. So I don't know why it will not put an automatic roof on, and why it crashed when I do a roof by picking points. Anyone have any ideas what I could have wrong in my structure to cause this?

Thanks,
JBme

[Abhann]

I had similar trouble yesterday with the "Mage's Tower" my son wanted me to try building.

Quick things to try:
- make sure all of the exterior walls are connected, just zoom around in 3D and if you can see drywall instead of your exterior anywhere that's a problem spot
- try File, Repair Project (SAVE A SECOND COPY FIRST!)
- try a different roof type (simpler or lower slope)
- go back to an earlier save or backup if you have one

Other:
- if you've done a lot of work on the project try making a new file with only the 4th floor and tower exterior walls to test with, and try just a 4th floor roof before adding tower
- it makes a difference if the tower is attached to the edge of the 4th floor or in the middle, in the middle was my type of problem

I had to duplicate my roof from a lower floor to get it working, but the experts on here will probably have a better solution.  If a curved roof won't go in automatically, I'm stuck, too.  But still learning.

Abhann

[Allan Chesney]

Hi JBme,

The usual cause of a Perimeter roof not working is, as Abhann suggested, a break in the wall. The automatic roof will only insert if the wall is continuous. If the wall is curved then the roof will automatically curve also.

As to why it is crashing with the Picking Points roof it is impossible to say without seeing the file. You could post it here if you like or email it to me if you prefer (alches AT iinet DOT net DOT au). The problem may be because the tower is on the same location as the 4th floor walls. It whould be OK if it is on it's own location. As a general rule any parts of a building where there are different wall heights should be on their own location.

Allan

[JBme]

Thanks for your help Allan and Abhann!

I can see that one wall was not joined properly and I've fixed that, and I've defined the tower to be on a separate "floor". It still will not build the roof, but I can put a roof on anywhere else, so it is clear that there is some pesky issue with the structure of the 4th floor and I'll find it eventually.

I have noticed in this case and in several other cases that when I have an error in my structure, TFP crashes when it can't cope. It would be a lot more helpful if instead it returned a useful informative error message. When it crashes, I know I have to go looking for what it can't cope with, and generally I find it, but only after some time.

Cheers,
JB

[Allan Chesney]

Hi JB and everyone,

The element where the most problems occur is walls. The wall element is probably the most complex element in the program, as it has many parts to it and multiples of trim options, so care needs to be exercised to make sure you do not introduce problems.  Following are a few suggestions that may help everyone to avoid bad wall joins:

• Generally it is best if walls can be drawn in one continuous process (as much as possible) and then be moved into place. For example: Draw the total exterior perimeter wall in one go (click, drag, click, drag, click, drag, etc and finally click to where you started, making sure it snaps together. If it doesn't snap together, extend both walls so they intersect each other and delete the two bits that stick out. Now move the individual walls to get the dimensions you want.  This works far better than trying to draw an exact length of wall, then starting another one at the corner and so on.
  
• Constant altering of wall joins can result in small fragments of wall being left behind. It is better to completely redo a section of walls if you have not got it right, than try to fiddle with it too much.
  
• If you are joining a wall onto the corner of an existing wall it is better to select one of the existing walls and extend it, than try to join another one into the existing corner.
  
• When a wall joins into another wall, make sure that you extend the wall beyond the centre of the other wall. It is better to extend the wall right through the other wall and delete the bit that sticks out the other side. This makes sure that you go to the middle of the wall and when you delete the bit you do not want, TFP heals the join completely and correctly.
  
• Avoid joining two walls end to end. Delete one section and extend the other right through to the adjoining wall.

If there is an undetected problem with a wall then it can cause problems with the floor, ceiling and roof when these are inserted by perimeter, so it important to get the walls right to avoid other problems.

HB: If you are getting repeated crashes it indicates there is a problem somewhere and walls are the most likely place, especially if the roof will not insert on the 4th floor. To find it, drag the mouse over the walls joins and you will see all the segments of wall in a join. In a normal join, there will just be a single trainagle in the centre of the join. If you have a series of triangles it is best to delete the walls that make up the join and redo them.

Check also that you do not have accidental breaks in walls. Each section of wall should have a green maker where you startted it and a red where you finished with a blue central one. If you have a break in the wall there will another set of red and green markers side by side in the wall where the break is and a blue central marker in the middle of each section. you can remove the break by deleting one section and extending the other to the adjoining wall.

It would be nice if TFP could detect all issues like this. You can try File / Repair. It will sometimes detect a corruption and delete it, so it is good to use this from time to time during the project. Hopefully one day it will detect all the corruptions. In the meantime, being careful drawing walls will probably prevent most, if not all, crashes.

Allan

[JBme]

Allan you are fantastic! - That is just SO helpful!!!

Thank you!!!

JB

[Allan Chesney]

Hi JB.

I am glad it was helpfull.

I may change your original subject line so that it refers to walls also, so that others with wall issues will see it.

Allan