To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.cadOpen lugnet.cad in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 CAD / 5681
5680  |  5682
Subject: 
Re: VB - parts and transformation matrices, Z-ordering, optional lines, bow-tied quads - help!
Newsgroups: 
lugnet.cad
Date: 
Tue, 27 Mar 2001 16:56:41 GMT
Viewed: 
529 times
  
Daniel Crichton wrote:
You are probably Pos-Multiplying the modeling Matrix, instead of
Pre-Multiplying.
I had that problem too !

OK, you've lost me here - I just applied the matrix calculation as-is from
the FAQ. What is the difference between Pos- and Pre- multiplying?

Imagine you have Modeling Matrix M and another matrix A to multiply it
by, like when you use command 1 (one, include of another .DAT file)
And you want to keep the final Matrix as a New modelling Matrix (NM)

so, you must be doing

NM = M . A

you should be doing

NM = A . M

Since Matrix multiplication is not commutative, the result is different.

Hope that helps.

See ya

Rui Martins



Message has 1 Reply:
  Re: VB - parts and transformation matrices, Z-ordering, optional lines, bow-tied quads - help!
 
Fixed it! When running the coords through the matrix I wasn't storing the new values in a separate array, so when it came to calculating the new Z coord on the 4-4ndis.dat and 4-4disc.dat parts I was using the translated X and Y coords in the calc (...) (24 years ago, 28-Mar-01, to lugnet.cad)

Message is in Reply To:
  Re: VB - parts and transformation matrices, Z-ordering, optional lines, bow-tied quads - help!
 
(...) Maybe, maybe not - I'm trying to build something that will help me draw complicated patterns on existing parts, such as the Darth Maul pattern (75% done). (...) OK, you've lost me here - I just applied the matrix calculation as-is from the (...) (24 years ago, 27-Mar-01, to lugnet.cad)

8 Messages in This Thread:



Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact

This Message and its Replies on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

Custom Search

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR