I created a body of a train using the extrude tool.

I would like eventually to have doors animation (photo attached).

I plan to proceed as follows:
1) create the doors shape with the extrude tool
2) create a hole in the body subtracting the doors shape
3) As the doors are not at the same level as the outside, creation of inward faces (extrude ?)
4) Creation of the doors themselves
5) Create the animation

Is this correct ?

Doors.jpg (50 Kb, 236 downloads) Doors

What I would do would be to create a separate section for the train's body that would house the door section, with the extrude tool. In doing this it would eliminate(hopefully) the production of any excess faces that would effect the remainder of the train's structure when using boolean subtractions.
Then procede as you had planned. but use a scaled cube with bevelled edges as the 'effector' object and create your door insets by 'drilling' a hole through your object. The faces created in doing this should already be inward facing for your interior view, so just merge them to cut down on polys. You can then create your doors to cover your entrance way and then animate them appropriately. Once done, optimize your object piece and then join it to the body of your train by using Paul Gausden's Butt Objects plug-in.

Creating an opening doorway for a train body that has been created by the extusion tool is not an easy thing to do succesfully.
The above is just one method and I'm sure others will have other methods that will achieve the same result.

Thanks for your reply.

If I reformulate the steps, it will be :

1) Create a limited body part to house the doors (to prevent too many polygons after Boolean operations, I must not work with the complete body).
2) Create the doors shape with a bevelled cube (not with the extrude tool)
3) Make the door insets : substract operation between doors shape and body part. This will create the inward faces for the interior view.
4) Merge interior faces to cut down on polygons counts.
5) Create the doors (extrusion tool : the doors are not flat)
6) Optimize the doors (???)
7) Create the animation
8) Add body sections (door body part will be cloned), texture

Questions :
a) Why not use the extrude tool at step 2 ? I'm not sure it will be compatible with the doors section : it is not flat.
b) What do you mean by "Paul Gausden's Butt Objects plug-in" ?

This message has been edited. Last edited by: DOM107,

doors2.jpg (18 Kb, 166 downloads)

The extrusion tool would be an option to create the doors. I should have realised that they would not be exactly flat.

In order to optimize the doors-Optimize Operation on the operations panel.

The 3DC Butt Objects plug-in is part of Paul Gausden's selection of plug-ins installed in his pack of plug-ins. You can get them from;
http://www31.brinkster.com/decapod/
if you don't already have them. Remember to use the applicable plug-ins for the version of 3DC you are currently using.

Basically the 3DC Butt objects plug-in allows perfect alingment of an objects bounding box against another on it's X, Y or Z Axis.

... so far I was not able to make the correct substract operation to create the recess needed for the doors (could not get the correct triangles inside).