Exhibit 10.15

                                                               November 30, 2004




To:      Smithfield Fiduciary LLC, as Buyer
         Bluegrass Growth Fund, L.P, as Buyer
         Bluegrass Growth Fund, Ltd., as Buyer
         Portside Growth & Opportunity Fund, as Buyer and Collateral Agent


Gentlemen:

      Reference is made is made to the Securities Purchase Agreement (as amended
or modified from time to time, the "Purchase Agreement"), dated as of November
30, 2004, among SpatiaLight, Inc. (the "Company") and each of you as "Buyers"
thereunder. Capitalized terms used and not otherwise defined herein have the
respective meanings ascribed to them in the Purchase Agreement, the "Notes" and
the "Pledge and Security Agreement" (as defined in the Purchase Agreement).

      In order to induce each of you to enter or accept into the Purchase
Agreement and the other Transaction Documents thereunder, and to purchase the
Notes to be issued and sold by the Company thereunder, SpatiaLight Korea, Inc.
("SLK"), a wholly-owned subsidiary of the Company, hereby:

            (a) acknowledges and confirms that it is a condition precedent to
      the Buyers' obligations under the Purchase Agreement that SLK execute and
      deliver this agreement to the Buyers and the Collateral Agent;

            (b) represents and warrants that SLK has determined that its
      execution, delivery and performance of this agreement directly benefits,
      and is within the corporate purposes and in the best interests of, SLK;

            (c) covenants and agrees that, so long as any Note is outstanding,
      SLK shall not (i) directly or indirectly, incur or guarantee, assume or
      suffer to exist any Indebtedness, other than Permitted Indebtedness, (ii)
      permit any of its Subsidiaries to, directly or indirectly, incur or
      guarantee, assume or suffer to exist any Indebtedness, other than
      Permitted Indebtedness, (iii) directly or indirectly, allow or suffer to
      exist any mortgage, lien, pledge, charge, security interest or other
      encumbrance (collectively, "Liens") upon or in any property or assets
      (including, without limitation, accounts and contract rights) owned by
      SLK, other than Permitted Liens, or (iv) permit any of its Subsidiaries
      to, directly or indirectly, allow or suffer to exist any Liens upon or in
      any property or assets (including, without limitation, accounts and
      contract rights) owned by any such Subsidiary, other than Permitted Liens


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            (d) covenants and agrees that, so long as any Note is outstanding,
      SLK shall not, without the prior written consent of the Collateral Agent,
      (i) pay, promise to pay or offer to pay, or authorize the payment of, any
      commission, bribe, pay-off or kickback that violates any applicable law or
      enter into any agreement pursuant to which any such commission, bribe,
      pay-off or kickback may or will at any time be paid, (ii) sell, transfer,
      lease or otherwise dispose of all or a substantial part of its assets
      (whether in a single transaction or in a series of transactions, related
      or otherwise), except disposal of assets in exchange for other assets
      comparable or superior to the assets disposed of in terms of type, value
      and quality and disposal of obsolete assets in the ordinary course of
      business, on ordinary commercial terms and on the basis of arm's-length
      arrangements, or (iii) undertake or permit any merger, consolidation or
      reorganization.

      In consideration of each Buyers' execution and delivery of the Transaction
Documents and acquiring the Notes thereunder, SLK hereby agrees to defend,
protect, indemnify and hold harmless each Buyer and each other holder of the
Notes and all of their stockholders, partners, members, officers, directors,
employees and direct or indirect investors and any of the foregoing Persons'
agents or other representatives, including (without limitation, those agents or
other representatives retained in connection with the transactions contemplated
by the Purchase Agreement (each, an "Indemnitee"), from and against any and all
actions, causes of action, suits, claims, losses, costs, penalties, fees,
liabilities, damages and expenses (irrespective of whether any such Indemnitee
is a party to the action for which indemnification hereunder is sought), and
including, without limitation, reasonable attorneys' fees and disbursements
(collectively, the "Indemnified Liabilities"), incurred by any Indemnitee as a
result of, or arising out of, or otherwise relating to, the breach of any
representation, warranty, covenant or agreement made by SLK in this agreement.
To the extent that the foregoing undertaking by SLK may be unenforceable for any
reason, SLK shall make the maximum contribution to the payment and satisfaction
of each of the Indemnified Liabilities that is permissible under applicable law.

      This agreement shall (a) be binding on SLK and its respective successors
and assigns, and (b) inure, together with all rights and remedies of the
Collateral Agent and the Buyers, to the benefit of the Collateral Agent and the
Buyers and their respective successors, transferees and assigns. Without
limiting the generality of clause (b) of the immediately preceding sentence, any
Buyer may assign or otherwise transfer its rights under this agreement to any
other Person, and such other Person shall thereupon become vested with all of
the benefits in respect thereof granted to the Buyers herein or otherwise.

      To the extent that SLK has or hereafter may acquire any immunity from
jurisdiction of any court or from any legal process (whether through service or
notice, attachment prior to judgment, attachment in aid of execution or
otherwise) with respect to itself or its property, SLK hereby irrevocably waives
such immunity in respect of its obligations under this agreement.

      This agreement shall be governed by, construed and interpreted in
accordance with the laws of the State of New York, except as required by
mandatory provisions of applicable law. Any legal action, suit or proceeding
with respect to this agreement may be brought in the courts of the State of New
York in the County of New York or the United States of America for the Southern
District of New York, and appellate courts thereof, and, by execution and
delivery of this agreement, SLK hereby accepts for itself and in respect of its
property, generally and unconditionally, the jurisdiction of the aforesaid
courts. SLK hereby expressly and irrevocably waives, to the fullest extent
permitted by law, any objection, including, without limitation, any objection to
the laying of venue or based on the grounds of forum non conveniens, which it
may now or hereafter have to the bringing of any such action, suit or proceeding
in such respective jurisdictions and consents to the granting of such legal or
equitable relief as is deemed appropriate by the court.



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         SLK and (by its acceptance of the benefits of this agreement) the
Collateral Agent and the Buyers waive any right it may have to trial by jury in
respect of any litigation based on, arising out of, under or in connection with
this agreement, or any course of conduct, course of dealing, verbal or written
statement or other action of the parties hereto.

         SLK irrevocably consents to the service of process of any of the
aforesaid courts in any such action, suit or proceeding by the mailing of copies
thereof by registered or certified mail (or any substantially similar form of
mail), postage prepaid, to SLK at its address provided herein, such service to
become effective 10 days after such mailing.

         Nothing contained herein shall affect the right of the Collateral Agent
or any Buyer to serve process in any other manner permitted by law or commence
legal proceedings or otherwise proceed against SLK or any property of SLK in any
other jurisdiction.


                                   Very truly yours,

                                   SpatiaLight Korea, Inc.


                                   By: /s/ Robert A. Olins
                                      -----------------------------------------
                                      Name:  Robert A. Olins
                                      Title: Chief Executive Officer
                                      Address: Five Hamilton Landing, Suite 100,
                                               Novato, CA 94949


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