3d Help!?!?

[pbooth11]

I have extruded and unioned objects in my drawing but i want to add materials to them to make my drawing look realistic.........the problem is that after extruding and unioning these object, they have all turned into one whole object therefore i cannot select the object i created for say a window to assignment any materials too it??

 

HEEEELLLLLPP.........im trying to complete my University assignment and have become really stuck

[ReMark]

You unioned everything together? And you didn't save the individual geometry like for the window for instance?

[pbooth11]

no, i extruded and unioned the objects i wanted (i.e windows doors) but once unioned/extruded them the whole thing became one solid object meaning i couldnt assign materials.....................

 

my tutor gave me this response: You can un-union these objecs by copying the object (so you have two identical objects side by side) and then using another object which completely encloses the portion you want to be separate you can use this object in one instance subtracting it from the object you want and in the other instance find the IN intersection of the two objects. This will result in the originl object being made into two objects.

BUT i couldnt get this process to work............?

[MikeScott]

If you have any backups, or autosaves, you might want to go back to before you told autocad that the windows were walls, etc.. (before the union thing).

 

Otherwise, slice like crazy or start over.. I don't see another option unless you want to make individual 3d surfaces "plating" the original item, except for the windows, and then turning the big thing into a window, and applying materials to the "shell" pieces you've made?

 

It might be a rendering pig.. and take hours to render.

 

Hopefully, you have autosave active and can use "options" to see where you've assigned them to be stored.

 

Good luck!

[MikeScott]

Your instructor means to "subtract" and "interfere" stuff that overlaps..that will work. Slice is another option.

[pbooth11]

  MikeScott said:

Your instructor means to "subtract" and "interfere" stuff that overlaps..that will work. Slice is another option.

 

So......if i make a copy of the building i have got...then subtract the copy from the original?

 

If i were to start from scratch how would i ensure that when extrude/union objects they dont all become one solid item???

[pbooth11]

  MikeScott said:

Your instructor means to "subtract" and "interfere" stuff that overlaps..that will work. Slice is another option.

 

So......if i make a copy of the building i have got...then subtract the copy from the original?

 

If i were to start from scratch how would i ensure that when extrude/union objects they dont all become one solid item???

 

i have uploaded my file incase you may be able to help via looking at it???

Ex1.05 bkup.dwgFetching info...

[ReMark]

You make sure objects do not become joined by NOT unioning them. A simple concept that you should immediately grasp right?

 

Something else that might help is to create layers for objects and assign materials to the layers instead of the individual objects.

[pbooth11]

  ReMark said:

You make sure objects do not become joined by NOT unioning them. A simple concept that you should immediately grasp right?

 

Something else that might help is to create layers for objects and assign materials to the layers instead of the individual objects.

 

But unioning them is the process to create windows isnt it?!

 

i tried creating layers a putting the internal face of a wall on one layers, external on another, windows on another etc n tried to create layers for materials etc but still everything became one solid object?

[ReMark]

Dude! Your building is one solid block! It's like a big block of cheese. What happened? The walls themselves really have no thickness.

 

What did you do? Did you extrude the building outline then create the "windows" by subtracting some material?

[pbooth11]

  ReMark said:

Dude! Your building is one solid block! It's like a big block of cheese. What happened? The walls themselves really have no thickness.

 

What did you do? Did you extrude the building outline then create the "windows" by subtracting some material?

 

i;

 

- created a wall, offset it for the wall thickness, extruded it by the height i wanted

- then make several recs and extruded them for windows and doors and subtracted and unioned them to created my proposed look

-after this stage i wanted to assign materials but thats when i realised everything was one solid solid! dont know where gone wrong........been following everything my tutor has taught?

[ReMark]

You obviously missed a couple of things.

 

How many "solid" buildings have you attempted to walk into lately? The inside of your building should be hollow. When you punched a window or a doorway into your building you should have been able to see inside. It appears you did not create walls. Do you understand?

[pbooth11]

  ReMark said:

You obviously missed a couple of things.

 

How many "solid" buildings have you attempted to walk into lately? The inside of your building should be hollow. When you punched a window or a doorway into your building you should have been able to see inside. It appears you did not create walls. Do you understand?

 

i think i do i noticed when i subtracted the recs from the wall the inner leaf disappeared. do i need to make sure that i have an inner leaf and out leaf of my wall to ensure that i can subtract i.e windows and doors????

[ReMark]

Your walls must have a thickness.

 

Draw a box (use the rectangle command). Offset it some distance. Invoke the Region command and select both boxes when prompted. Invoke the Subtract command and subtract the inner box from the outer box. Extrude the object. You should now have a box that you can 1) look into and 2) has "walls" equal to the distance you used as the offset. Try it now.

[pbooth11]

  ReMark said:

Your walls must have a thickness.

 

Draw a box (use the rectangle command). Offset it some distance. Invoke the Region command and select both boxes when prompted. Invoke the Subtract command and subtract the inner box from the outer box. Extrude the object. You should now have a box that you can 1) look into and 2) has "walls" equal to the distance you used as the offset. Try it now.

 

 

is this correct......?

trial box.dwgFetching info...

[ReMark]

You did not subtract the inner box from the outer box as per my instructions.

[ReMark]

Here is your building with 1) walls and 2) a "window" punched through the wall. I left off the roof so you could see that it is hollow inside just like a real building would be.

 

[pbooth11]

  ReMark said:

Here is your building with 1) walls and 2) a "window" punched through the wall. I left off the roof so you could see that it is hollow inside just like a real building would be.

 

[ATTACH]18268[/ATTACH]

 

when i SU the inner from outer wall i got a response of 'null region created - deleted' ??

 

i understand how it should look but i dont seem to be able to correct the process u indicated...........how did u create this from my drawing ^^^ ??

[MikeScott]

  ReMark said:

You make sure objects do not become joined by NOT unioning them. A simple concept that you should immediately grasp right?

 

lol, be nice...

 

A window (glass) is just a 3d solid that is made transparent by the materials applied to it.

 

The union command takes all of your 3d solids (that you select during the command) erases them, and then redraws only the exposed surfaces of them, and creates a single solid which, from the outside, looks like the same thing.

 

You MIGHT perform the union command on a window, if you had a few pieces of glass that you wanted to become one piece.

 

 

  Quote

when i SU the inner from outer wall i got a response of 'null region created - deleted' ??

 

subtract command asks for the "object to have material removed from" and then asks for the object(s) that will subtract material.

 

Sounds to me like you selected the inside box first.. you need to select the outside box first.

[pbooth11]

  MikeScott said:

lol, be nice...

 

A window (glass) is just a 3d solid that is made transparent by the materials applied to it.

 

The union command takes all of your 3d solids (that you select during the command) erases them, and then redraws only the exposed surfaces of them, and creates a single solid which, from the outside, looks like the same thing.

 

You MIGHT perform the union command on a window, if you had a few pieces of glass that you wanted to become one piece.

 

ye i understand all the concept of applying materials etc just dnt undertand when subtracting and unioning objects they become one solid object therefore i cnt apply materials?? how do i ensure that the object i created for a window then subtract it from the wall stays single so i can apply materials too it?.....