ENGINEERING ANIMATION, INC.

                                                                EXHIBIT 10.6
                    1999 NONQUALIFIED STOCK OPTION AGREEMENT

                                (NON-PLAN OPTION)

         THIS  AGREEMENT  is made as of the 30th day of April,  1999 (the "Grant
Date")  between  ENGINEERING  ANIMATION,   INC.,  a  Delaware  corporation  (the
"Company"), and Robert Nierman (the "Optionee").

                                   WITNESSETH:

         WHEREAS,  the Board of Directors of the Company recognizes the value of
granting  stock  options  to  employees  of the  Company a means of  attracting,
retaining and rewarding persons of ability as key employees and motivating these
employees to exert their best efforts on behalf of the Company; and

         WHEREAS,  the Board of  Directors  of the  Company  (the  "Board")  has
decided to grant to the Optionee an option to purchase  shares of the  Company's
common stock, $0.01 par value per share ("Common Stock").

         NOW THEREFORE, the parties hereby agree as follows:

         1.       Grant. The Company grants to the Optionee an option (the
"Option") to purchase  225,000  shares of the  Company's  Common Stock at a per-
share price of $15.907  (the  "Option  Price"),  on the terms and subject to the
conditions set forth in this Agreement.

         2.  Timing and  Duration  of  Exercise.  Subject to the  provisions  of
Section 3 of this Agreement,  the duration of the Option shall be for the period
beginning on the Grant Date and continuing  through the close of business on the
10-year  anniversary  of the Grant  Date (the  "Option  Period").  Except to the
extent otherwise provided in this Agreement, the Optionee shall become vested in
the Option as follows:

o    Fifty-six  thousand two hundred fifty (56,250) shares shall vest as of each
     of the one-year,  two-year,  three-year, and four-year anniversaries of the
     Grant Date.

         The Option shall be  exercisable by the Optionee at any time during the
Option Period to the extent it is vested.


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         3.       Exercise in the Event of Death or Other Termination.
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                  (a) If the  Optionee  dies while an employee of the Company or
         terminates  the  employment  relationship  with the Company  because of
         "permanent disability," as defined in Code Section 22(e)(3), the Option
         may be exercised, to the extent that the Optionee could have done so at
         the date of the Optionee's  termination of employment  because of death
         or permanent  disability  (i.e.,  to the extent the Option is vested at
         that  time),  by the person or persons  to whom the  Optionee's  rights
         under the Option pass by will or  applicable  law, or if no such person
         has such right, by his/her executors or administrators, at any time, or
         from time to time,  within one year after the date of such  termination
         of employment or consulting or advisor relationship, but not later than
         the expiration date specified in Section 5(c) of this Agreement.

                  (b)  If  the  Optionee's  employment  shall  terminate  due to
         "retirement" as defined below, the Optionee may exercise the Option, to
         the  extent  that the  Optionee  could  have done so at the date of the
         Optionee's  termination of employment due to retirement  (i.e.,  to the
         extent the Option is vested at that time), at any time, or from time to
         time,  within  three months of such  retirement  but not later than the
         expiration  date  specified in Section 5(c) of this  Agreement.  If the
         Optionee dies following his/her  retirement and prior to exercising the
         portion  of the Option  that has not  expired as of the date of his/her
         death, then,  notwithstanding the preceding  sentence,  that portion of
         the Option  shall  remain  exercisable  until the first to occur of the
         expiration date specified in Section 5(c) of this Agreement or one year
         after the date of the Optionee's  death.  "Retirement"  for purposes of
         this Agreement shall mean the termination of the Optionee's  employment
         on or after the date he/she attains age 65.

                  (c) Notwithstanding  anything in this Section to the contrary,
         if the  Optionee's  employment  relationship  is terminated  for cause,
         his/her  ability to exercise any portion of the Option shall  terminate
         on the date of his/her  termination  of  employment.  For this purpose,
         termination for "cause" means

                   (i) the  commission of an action  against or in derogation of
                  the  interests of the Company  which,  if proven in a court of
                  law,  would  constitute  a  violation  of a  criminal  code or
                  similar law;

                  (ii)     divulging the Company's confidential information; or

                  (iii)  the   performance   of  any  similar  action  that  the
                  Committee, in its sole discretion, may deem to be sufficiently
                  injurious to the interest of the Company to  constitute  cause
                  for termination.

(d)      If the  Optionee's  employment is terminated  for any reason other than
         those described in subsections (a), (b) or (c) of this Section,  he/she
         may  exercise the Option,  to the extent that the  Optionee  could have
         done so at the date of the Optionee's  termination of employment (i.e.,
         to the extent the Option is vested at that time),  at any time, or from
         time to time, within three months of the date of his/her termination of
         employment,  consulting or advisor relationship, but not later than the
         end of the Option Period.

         4.       Method of Exercise.  The Option, or any part of it, shall be
exercised by written notice  directed to the Corporate  Secretary of the Company
at the Company's  principal  office in Ames,  Iowa. Such notice must satisfy the
following requirements:

                  (a) The notice must state the Grant Date, the number of shares
         of Common  Stock  subject to the grant,  the number of shares of Common
         Stock with respect to which the Option is being  exercised,  the person
         in whose name the stock  certificate or certificates for such shares of
         Common Stock is to be  registered  and the person's  address and Social
         Security number (or if more than one person,  the names,  addresses and
         Social Security numbers of such persons).

                  (b) The notice  shall be  accompanied  by check,  bank  draft,
         money order or other cash  payment or by delivery of a  certificate  or
         certificates,  properly endorsed, for shares of Common Stock equivalent
         in Fair Market Value on the date of exercise to the Option Price, or by
         a combination  of cash and shares,  in full payment of the Option Price
         for the number of shares specified in the notice.

                  (c)  The  notice  shall  contain  such   representations   and
         agreements  as to the holder's  investment  intent with respect to such
         shares of Common Stock as may be satisfactory to the Board.

                  (d) The  notice  must  be  signed  by the  person  or  persons
         entitled to exercise  the Option and, if the Option is being  exercised
         by any person or persons other than the  Optionee,  be  accompanied  by
         proof,  satisfactory  to the  Board,  of the  right of such  person  or
         persons to exercise the Option.

         The  exercise  may be with  respect to any one or more shares of Common
Stock covered by the Option,  reserving  the  remainder for a subsequent  timely
exercise.  The Company shall make prompt delivery of such shares;  provided that
if any law or regulation requires the Company to take any action with respect to
such  shares  before the  issuance  thereof,  then the date of  delivery of such
shares  shall be extended  for the period  necessary  to take such  action;  and
provided  further that the Company  shall have no obligation to deliver any such
certificate  unless  and  until  appropriate  provision  has  been  made for any
withholding  taxes in  respect  of such  exercise.  The  Optionee  may  elect to
surrender shares of Common Stock previously  acquired by the Optionee or to have
the Company  withhold  shares that would have otherwise been issued  pursuant to
the  exercise of the Option in order to satisfy all or a portion of any such tax
withholding obligation.

         5.       Termination of Option; Bar to Exercise.
                  --------------------------------------

                  (a) The  Board  may at any time  terminate  the  Option  if it
         shall,  in the  reasonable  exercise  of its  judgment,  find  that the
         Optionee has  disclosed,  without the written  consent of an authorized
         officer of the  Company,  to any person not  employed  by or engaged to
         render  services to the Company,  any  confidential  information of the
         Company  or has  engaged  in  competition  with the  Company  or in any
         activities otherwise contrary to the best interests of the Company. The
         right to exercise this Option has been granted, and the compensation to
         be  realized  in the  event of  exercise  has been  provided,  upon the
         express  understanding that the Optionee shall refrain from engaging in
         any activities contrary to the best interests of the Company.

                  (b) The Option may not be  exercised  if such  exercise  could
         constitute a violation of any applicable federal, state or other law or
         regulation.

                  (c) The Option may not be exercised  after the last day of the
         Option Period,  as defined in Section 2 of this  Agreement,  subject to
         the limitation in Section 3 of this Agreement, if applicable.

         6.  Change in  Control.  As of the  effective  date of any  "Change  in
Control,"  as defined  below,  the Option shall become fully vested and shall be
exercisable  with respect to any portion of the shares of Common  Stock  subject
thereto at any time prior to the  expiration  date  specified in Section 5(c) of
this Agreement  (subject to Section 3 of this  Agreement).  For this purpose,  a
"Change in Control" of shall be deemed to have  occurred if the  conditions  set
forth in any one or more of the following paragraphs shall have been satisfied:

                  (a) Any Person other than a trustee or other fiduciary holding
         securities  under  an  employee  benefit  plan  of  the  Company,  or a
         corporation  owned  directly or indirectly by the  stockholders  of the
         Company in  substantially  the same  proportions as their  ownership of
         Shares of the Company,  or other than a Person whose stock ownership is
         approved by a vote of  two-thirds  (2/3) of the  Directors  who are not
         affiliated with such Person), becomes the Beneficial Owner, directly or
         indirectly,  of securities of the Company  representing  50% or more of
         the combined voting power of the Company's then outstanding securities;
         or

                  (b)  During  any  period  of  two  consecutive  fiscal  years,
         individuals who at the beginning of such period constitute the Board of
         Directors (and any new Director,  whose election the Board of Directors
         was approved by a vote of at least  two-thirds  (2/3) of the  Directors
         then still in office who either were  Directors at the beginning of the
         period or whose  election was  previously so  approved),  cease for any
         reason to constitute a majority thereof; or

                  (c) The  stockholders  of the  Company  approve  (a) a plan of
         complete  liquidation of the Company;  or (b) an agreement for the sale
         or disposition of all or substantially all the Company's assets; or (c)
         a merger or  consolidation  of the Company with any other  corporation,
         other than a merger or  consolidation  which would result in the voting
         securities  of  the  Company  outstanding   immediately  prior  thereto
         continuing to represent  (either by remaining  outstanding  or by being
         converted into voting securities of the surviving entity), at least 50%
         of the combined  voting  securities  of the Company (or such  surviving
         entity) outstanding immediately after such merger or consolidation; or

                  (d)      The Board of Directors agrees by a two-thirds (2/3)
         vote, that a Change in Control of the Company has occurred.

         However,  in no event  shall a Change  in  Control  be  deemed  to have
         occurred,  with respect to an Optionee,  if that  Optionee is part of a
         purchasing group which  consummates the Change in Control  transaction.
         An Optionee  shall be deemed "part of a purchasing  group" for purposes
         of the preceding  sentence if the Optionee is an equity  participant or
         has agreed to become an equity participant in the purchasing company or
         group  (except for (i) passive  ownership of less than 3% of the shares
         of the purchasing company; or (ii) ownership or equity participation in
         the  purchasing  company or group which is  otherwise  not deemed to be
         significant, as determined prior to the Change in Control by a majority
         of the disinterested Directors of the Company).

          7.  Rights Not  Conferred.  The Option  shall not be  affected  by any
change in the nature of the  Optionee's  employment  with the Company so long as
the Optionee continues to be employed by the Company.  Nothing contained in this
Agreement  shall confer upon the Optionee any right with respect to  continuance
of  employment  or other  relationship  with the Company or interfere in any way
with the right of the Company to terminate the employment of the Optionee at any
time.

         8.       Nontransferability.  The Option shall not be transferable
other  than by will or by the  laws of  descent  and  distribution.  During  the
lifetime of the Optionee,  the Option shall be exercisable  only by the Optionee
or by the Optionee's guardian or legal representative.

         9.       No Rights as a Stockholder.  The Optionee shall not have any
rights as a  stockholder  with respect to any shares of Common Stock  subject to
the Option  prior to the date of issuance to the  Optionee of a  certificate  or
certificates for such shares.

         10.  Option  Subject to this  Agreement.  The granting of the Option is
being made pursuant to this Agreement and the Option shall be  exercisable  only
in  accordance  with the  applicable  terms  of this  Agreement.  The  Agreement
contains  certain  definitions,  restrictions,  limitations  and other terms and
conditions all of which shall be applicable to the Option.

         11. Adjustments in Event of Change in Common Stock. In the event of any
increase  or  decrease  in the  number of shares of issued  Common  Stock of the
Company  resulting from a subdivision or consolidation of shares whether through
reorganization, payment of a share dividend or other increase or decrease in the
number of such shares  outstanding  effected without receipt of consideration by
the  Company,  distribution  of assets to  stockholders  or the  assumption  and
conversion of outstanding  options in an acquisition of the Company,  the number
and  kind  of  shares  subject  to the  Option,  and  the  Option  Price  may be
appropriately  adjusted  consistent with such change in such manner as the Board
may deem equitable to prevent substantial  dilution or enlargement of the rights
granted to or available for the Optionee;  provided, however, that no adjustment
in the number of shares subject to the Option shall be made, except in the event
that such adjustment,  together with all respective prior  adjustments that were
not made as a result of this provision, involve a net change of more than 10%.

         12.  Withholding of Taxes. Upon the exercise of an Option,  the Company
may deduct any Federal, state or local taxes required by law to be withheld with
respect to such exercise.  Any holder of an Option may elect to surrender shares
of  Common  Stock  previously  acquired  by the  holder  or to have the  Company
withhold  shares that would have otherwise been issued to the holder pursuant to
the exercise of an Option,  the number of such withheld or surrendered shares to
be  sufficient  to satisfy  all or a portion of the  income tax  liability  that
arises upon such exercise.

         13.  Severability.  If any provision or portion of this Agreement shall
be  determined  to be invalid or  unenforceable  for any reason,  the  remaining
provisions of this Agreement  shall be unaffected and shall remain in full force
and effect in such jurisdiction, and any such invalid or unenforceable provision
shall not be considered invalid or unenforceable in any other jurisdiction.

         14.      Binding Effect.  This Agreement shall be binding upon the
heirs, executors, administrators and successors of the parties.


         15. Administration.  The Agreement shall be administered by a Committee
consisting  of two or more  members of the Board of Directors of the Company who
are appointed  from time to time by said Board of Directors  (the  "Committee").
Subject to the express provisions of the Agreement, the Committee shall have the
power to interpret  the  Agreement,  to  prescribe,  amend and rescind rules and
regulations relating to the Agreement,  to determine the terms and provisions of
Optionee's  individual  option  agreements  (which need not be identical) and to
make such other  determinations  as it deems  necessary or advisable in carrying
out the  administration  of the  Agreement.  All  decisions of the  Committee on
matters within its jurisdiction  shall be conclusive and binding.  To the extent
required  to  comply  with the  relevant  provisions  of Rule  16b-3  under  the
Securities Exchange Act of 1934, each member of the Committee shall qualify as a
"non-employee director," as defined in Rule 16b-3 or in any successor definition
adopted by the  Securities  and Exchange  Commission.  No member of the Board of
Directors or the Committee shall be liable for any action taken or determination
made in good faith.

         16.      Other Definitions.
                  -----------------

                  (a) "Beneficial Owner" shall have the meaning ascribed to such
         term in Rule  13d-3 of the  General  Rules  and  Regulations  under the
         Securities Exchange Act of 1934.

                  (b)      "Common Stock" shall mean the Company's $0.01 par
          value common stock.

                  (c) "Person"  shall have the meaning  ascribed to such term in
         Section  3(a)(9)  of the  Securities  Exchange  Act of 1934 and used in
         Sections 13(d) and 14(d) thereof,  including a group defined in Section
         13(d).