【转帖】nested blocks
 

nested blocks

nested blocks
given below is my function to read a block reference/insert entity
bool readblockreference(oddbentityptr pentityptr)
{
oddbblockreferenceptr pblockreferenceptr = pentityptr;
odgematrix3d blocktransformmatrix = pblockreferenceptr->blocktransform();
odgepoint3d position = pblockreferenceptr->position();
oddbblocktablerecordptr pblocktablerecordptr = pblockreferenceptr->blocktablerecord().safeopenobject();
oddbobjectiteratorptr pobjectiteratorptr = pblocktablerecordptr->newiterator();
oddbentityptr pentity;
while(!pobjectiteratorptr->done())
{
pentity = pobjectiteratorptr->entity();
pentity->transformby(blocktransformmatrix);
readentity(pentity);
pobjectiteratorptr->step();
}
return true;
}
the function readentity() calls readblockreference() when the entity is a block reference/insert. the above code works fine for simple blocks. i have a problem for nested blocks (blocks containing blocks). the nested blocks are placed incorrectly in space. i know that the problem lies with the fact that i am doing something wrong with the blocktransformationmatrix variable and i am not doing anything with the position variable. just dont know what.
please help.

deelip
# 17th november 2003, 01:38 am

moderator join date: mar 2002
posts: 2,994
blocktransform matrix contains translation so position should not be applied together with blocktransform matrix.
you get wrong results for nested blocks because
1. transforms of all levels should be applied. each block insertion has it's own transform and for nested blocks a transformation stack should be used.
2. not all entities can be transformed using transformby(). for example text can't be transformed non-uniformly (if x and y scales are different for example).
3. block's base point should be taken into account.
sergey slezkin

sslezkin
# 17th november 2003, 04:40 am

registered user join date: sep 2003
location: goa, india
posts: 16

thanks
thanks for your quick reply

deelip

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blocktransform matrix contains translation so position should not be applied together with blocktransform matrix.
you get wrong results for nested blocks because
1. transforms of all levels should be applied. each block insertion has it's own transform and for nested blocks a transformation stack should be used.
2. not all entities can be transformed using transformby(). for example text can't be transformed non-uniformly (if x and y scales are different for example).
3. block's base point should be taken into account.
sergey slezkin

thanks
thanks for your quick reply