Exhibit 2.1

         AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED AGREEMENT AND 
                     PLAN OF ACQUISITION AND AMALGAMATION
                                        
     This Amendment No. 2 (the "Second Amendment") to the Second Amended and
Restated Agreement and Plan of Acquisition and Amalgamation by and among
Autodesk, Inc. ("Parent"), Autodesk Development B.V. ("Dutchco"), 9066-9771
Quebec Inc. ("Amalgamation Sub"), Autodesk Canada Inc. ("ACI"), 9066-9854 Quebec
Inc ("Giants Quebec") and Discreet Logic Inc (the "Company") dated as of
November 18, 1998 (the "Second Amended and Restated Agreement"), as amended by
the Amendment dated December 18, 1998 (the "First Amendment"), is entered into
by and among each of the parties to the Second Amended and Restated Agreement
effective as of January 18, 1999.

                                    RECITALS
                                        
     WHEREAS, Parent, Dutchco, Amalgamation Sub, ACI, Giants Quebec and the
Company entered into an Agreement and Plan of Acquisition and Arrangement dated
as of August 20, 1998, which was subsequently amended and restated in its
entirety by the parties in the Amended and Restated Agreement and Plan of
Acquisition and Amalgamation dated as of September 23, 1998, and again amended
and restated in its entirety in the Second Amended and Restated Agreement;

     WHEREAS, the Second Amended and Restated Agreement provides, among other
things, that upon the terms and subject to the conditions thereof, immediately
following the amalgamation (the "Amalgamation") of Amalgamation Sub, Giants
Quebec (to which ACI will assign, prior to the Amalgamation, substantially all
its assets) and the Company, whereupon each outstanding Company Common Share
shall be converted into one Class B Share of the Continuing Corporation
resulting from the Amalgamation, the Class B Shares of the Continuing
Corporation automatically will be, based on the prior election of their holder,
either (i) redeemed by the Continuing Corporation for 0.48 exchangeable shares
in the share capital of the Continuing Corporation, subject to proration in
certain instances, or (ii) converted into units comprised of one Class E Share
and one Class F Share of the Continuing Corporation, which units will be
acquired by Dutchco in exchange for 0.48 shares of Parent Common Stock; and

     WHEREAS, the parties now desire to amend the Exchange Ratio set forth in
the Second Amended and Restated Agreement, and to make certain representations
and warranties to each other as of the date hereof;


                                   AGREEMENT
                                        
     NOW, THEREFORE, in consideration of the foregoing and of the mutual
covenants and agreements set forth herein and for other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged, the
parties hereto agree as follows:

 
     1.  Exchange Ratio.  The recitals to the Second Amended and Restated
         --------------                                                  
Agreement are hereby amended such that all occurrences in the recitals of the
term "0.48" shall be replaced in each case with "0.33" and the term "Exchange
Ratio" shall be defined as 0.33.

     2.  Representations and Warranties of the Company.  The Company hereby
         ---------------------------------------------                     
represents to each member of the Parent Group as of the date hereof, subject to
the Company Disclosure Schedule dated as of the date of the Original Agreement:

           (a)     Authority. The Company has all necessary corporate power and
authority to execute and deliver this Second Amendment and to perform its
obligations hereunder and to consummate the transactions contemplated hereby.
The execution and delivery of this Second Amendment by the Company and the
consummation by the Company of the transactions contemplated thereby have been
duly and validly authorized by all necessary corporate action and no other
corporate proceedings on the part of the Company are necessary to authorize this
Second Amendment or to consummate the Transactions, other than the approval and
adoption of the Second Amended and Restated Agreement, as amended, and
confirmation of by-law No. 1998-1 approving the Amalgamation by the holders of
at least sixty-six and two-thirds percent (66 2/3%) of the outstanding Company
Shares who are permitted to, and who, vote at the Company Shareholders' Meeting
in accordance with the Quebec Act. The Board of Directors of the Company has
determined that it is advisable and in the best interests of the Company's
shareholders for the Company to enter into a business combination with Parent
upon the terms and subject to the conditions of the Second Amended and Restated
Agreement, as amended, and to recommend that the shareholders of the Company
approve same. This Second Amendment has been duly and validly executed and
delivered by the Company, and assuming the due authorization, execution and
delivery hereof by each member of the Parent Group, constitutes a legal, valid
and binding obligation of the Company.


           (b)     No Conflict. The execution and delivery of this Second
Amendment by the Company does not, and the performance of the Company's
obligations under this Second Amendment will not, (i) conflict with or violate
the Articles of Incorporation or By-Laws or equivalent organizational documents
of the Company or any of its subsidiaries, (ii) conflict with or violate any
law, rule, regulation, order, judgment or decree applicable to the Company or
any of its subsidiaries or by which its or any of their respective properties is
bound or affected, or (iii) result in any breach of or constitute a default (or
an event that with notice or lapse of time or both would become a default), or
impair the Company's or any of its subsidiaries' rights or, to the Company's
knowledge, alter the rights or obligations of any third party under, or give to
others any rights of termination, amendment, acceleration or cancellation of any
Covered Agreement, or result in the creation of a lien or encumbrance on any of
the properties or assets of the Company or any of its subsidiaries pursuant to
any note, bond, mortgage, indenture, contract, agreement, lease, license,
permit, franchise or other instrument or obligation to which the Company or any
of its subsidiaries is a party or by which the Company or any of its
subsidiaries or its or any of their respective properties is bound or affected,
except in the case of (ii) and (iii) for any such conflicts, violations,
breaches, defaults, terminations, cancellations or accelerations which would not
have a Material Adverse Effect.

 
           (c)     Required Filings. The execution and delivery of this Second
Amendment by the Company does not, and the performance of the transactions
contemplated hereby and by the Second Amended and Restated Agreement, as
amended, will not, require any consent, approval, authorization or permit of, or
filing with or notification to, any governmental or regulatory authority,
domestic or foreign, to be made or obtained by the Company, except (i) for
applicable requirements, if any, of the Securities Act, the Exchange Act, Blue
Sky Laws, the pre-merger notification requirements of the HSR Act, the QSA and
other relevant Canadian securities statutes, filing with Industry Canada under
the Investment Canada Act (Canada), filing under the Competition Act (Canada)
and the filing and recordation of appropriate documents as required by the
Quebec Act in connection with the Amalgamation and (ii) where the failure to
obtain such consents, approvals, authorizations or permits, or to make such
filings or notifications, would not prevent or materially delay consummation of
the Amalgamation, or otherwise prevent or materially delay the Company from
performing its obligations under this Second Amendment or the Second Amended and
Restated Agreement, as amended, or would not otherwise have a Material Adverse
Effect.

           (d)     Opinion of Financial Advisor. The Company has received an
oral opinion from its financial advisor, Volpe Brown Whelan & Company (to be
subsequently confirmed in writing), to the effect that, as of the date hereof,
the consideration to be received by the shareholders of the Company pursuant to
the Second Amendment and the Second Amended and Restated Agreement, as amended,
is fair to such shareholders from a financial point of view.

     3.  Representations and Warranties of the Parent Group.  Each member
         --------------------------------------------------              
of the Parent Group hereby represents to the Company as of the date hereof,
subject to the Parent Disclosure Schedule dated as of the date of the Original
Agreement:

           (a)     Authority.  Each member of the Parent Group has all necessary
corporate power and authority to execute and deliver this Second Amendment and
to perform its obligations hereunder and to consummate the transactions
contemplated hereby.  The execution and delivery of this Second Amendment by
each member of the Parent Group and the consummation by each member of the
Parent Group of the transactions contemplated hereby have been duly and validly
authorized by all necessary corporate action on the part of each member of the
Parent Group, and no other corporate proceedings on the part of any such member
are necessary to authorize this Agreement or to consummate the Transactions
(other than the approval of the Parent Stock Issuance and/or the adoption of the
Second Amendment and Restated Agreement, as amended, and the transactions
contemplated thereby by the requisite vote of the stockholders of Parent, to the
extent necessary).  The Boards of Directors of Parent and Dutchco have
determined that it is advisable and in the best interest of Parent's
stockholders and Dutchco's stockholder for Parent and Dutchco to enter into a
business combination with the Company upon the terms and subject to the
conditions of the Second Amended and Restated Agreement, as amended (including
by this Second Amendment) and to recommend that the stockholders of Parent
approve same.  This Second Amendment has been duly and validly executed and
delivered by each member of the Parent Group and, assuming the due
authorization, execution and delivery by the Company, constitutes a legal, valid
and binding obligation of each member of the Parent Group.

 
           (b)     No Conflict. The execution and delivery of this Second
Amendment by each member of the Parent Group do not, and the performance of the
Company's obligations under this Second Amendment by each member of the Parent
Group will not, (i) conflict with or violate the Certificate of Incorporation or
By-Laws (or similar charter documents, as the case may be) of any member of the
Parent Group, (ii) conflict with or violate any law, rule, regulation, order,
judgment or decree applicable to Parent or any of its subsidiaries or by which
its or their respective properties are bound or affected, or (iii) result in any
breach of or constitute a default (or an event which with notice or lapse of
time or both would become a default) under, or impair Parent's or any of its
subsidiaries' rights or alter the rights or obligations of any third party
under, or to the knowledge of Parent, give to others any rights of termination,
amendment, acceleration or cancellation of, any material contract or result in
the creation of a lien or encumbrance on any of the properties or assets of
Parent or any of its subsidiaries pursuant to any material note, bond, mortgage,
indenture, contract, agreement, lease, license, permit, franchise or other
instrument or obligation to which Parent or any of its subsidiaries is a party
or by which Parent or any of its subsidiaries or its or any of their respective
properties are bound or affected, except in the case of (ii) and (iii) for any
such breaches, defaults or other occurrences that would not have a Material
Adverse Effect.

           (c)     Required Filings.  The execution and delivery of this Second
Amendment by each member of the Parent Group does not, and the performance of
the transactions contemplated hereby and by the Second Amended and Restated
Agreement, as amended will not, require any material consent, approval,
authorization or permit of, or filing with or notification to, any governmental
or regulatory authority, domestic or foreign, except (i) for applicable
requirements, if any, of the Securities Act, the Exchange Act, the Blue Sky
Laws, the pre-merger notification requirements of the HSR Act, relevant Canadian
securities statutes, filing with Industry Canada under the Investment Canada Act
(Canada), filing under the Competition Act (Canada) and the filing and
recordation of appropriate merger or other documents as required by the Quebec
Act and (ii) where the failure to obtain such consents, approvals,
authorizations or permits, or to make such filings or notifications, would not
prevent or materially delay consummation of the Amalgamation, or otherwise
prevent any member of the Parent Group from performing its respective
obligations under this Second Amendment, or the Second Amended and Restated
Agreement, as amended, and would not have a Material Adverse Effect.

           (d)     Board Approval. The Board of Directors of Parent has, as of
the date of this Second Amendment, determined to recommend that the stockholders
of Parent approve the Parent Stock Issuance.

     4.  Termination.   Article VII of the Second Amended and Restated Agreement
         -----------                                                            
is hereby amended as follows:

           (a)     Section 7.3(b)(i)(C) shall be amended such that the reference
to "February 23, 1999" shall be replaced with a reference to "March 23, 1999".

           (b)     Section 7.3(c)(ii) shall be amended such that the reference
to "February 23, 1999" shall be replaced with a reference to "March 23, 1999".

 
     5.  General.
         ------- 

           (a)     All other terms and conditions of the Second Amended and
Restated Agreement, as amended by the First Amendment, including without
limitation the representations, warranties, covenants and agreements of the
respective parties, shall remain in full force and effect without other or
further amendment or modification, fully applying to the Second Amended and
Restated Agreement as amended by the First Amendment and this Second Amendment.

           (b)     Each capitalized term used in this Second Amendment but not
defined herein shall have the meaning ascribed to it in the Second Amended and
Restated Agreement.  All section references in this Agreement are to the Second
Amended and Restated Agreement.

           (c)     This Second Amendment may be executed in one or more
counterparts, each of which shall be deemed an original, but all of which, when
taken together, shall constitute one and the same instrument.

                 [Remainder of  Page Intentionally Left Blank]

 
           IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be executed by their respective duly authorized officers as of the date first
above written.


                                    "Parent"                      
                                                                  
                                    Autodesk, Inc.                
                                                                  
                                                                  
                                    By: /s/ CAROL A. BARTZ        
                                        -----------------------   
                                        Carol A. Bartz            
                                        Chief Executive Officer   
                                                                  
                                                                  
                                                                  
                                    "Dutchco"                     
                                                                  
                                    Autodesk Development B.V.     
                                                                  
                                                                  
                                    By: /s/ MICHAEL E. SUTTON     
                                        ---------------------     
                                        Michael E. Sutton         
                                        Directeur                 
                                                                  
                                                                  
                                                                  
                                    "Amalgamation Sub"            
                                                                  
                                    9066-9771 Quebec Inc.         
                                                                  
                                                                  
                                    By: /s/ MARCIA K. STERLING    
                                        ----------------------    
                                        Marcia K. Sterling        
                                        Secretary                 
                                                                  
                                                                  
                                                                  
                                    "ACI"                         
                                                                  
                                    Autodesk Canada Inc.          
                                                                  
                                                                  
                                    By: /s/ CAROL A. BARTZ        
                                        ------------------        
                                        Carol A. Bartz            
                                        President                  

 
                                     "Giants Quebec"                    
                                                                        
                                     9066-9854 Quebec Inc.              
                                                                        
                                                                        
                                     By: /s/ MARCIA K. STERLING         
                                         ----------------------         
                                         Marcia K. Sterling             
                                         Secretary                      
                                                                        
                                                                        
                                     "Company"                          
                                                                        
                                     Discreet Logic Inc.                
                                                                        
                                                                        
                                     By: /s/ FRANCOIS PLAMONDON         
                                         ----------------------         
                                         Francois Plamondon             
                                         Executive Vice President and   
                                         Chief Financial Officer