PRB: Direct3D Spotlight Range Attenuation Different in DX5/DX6

ID: Q196371

The information in this article applies to:

Microsoft DirectX Software Development Kit, version 5.0, 5.0a, 5.2, 6.0

SYMPTOMS

There are applications that behave differently under DirectX 5.0 and DirectX 6.0 when you use spotlight range attenuation in Direct3D Retained Mode.

CAUSE

The "view-dependent specular highlighting" option was turned on in DirectX 5.0 by default and turned off in DirectX 6.0. This change should not affect any applications developed using DirectX 5.0.

RESOLUTION

If you are going to use spotlight range attenuation in your application, make sure that you set the following render mode to ensure that you get the correct behavior on all versions of Direct3D Retained Mode without relying on the default values:

   IDirect3DRMDevice2 : D3DRMRENDERMODE_VIEWDEPENDENTSPECULAR

Without this flag, your application might behave differently depending on which version of DirectX is installed.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

Additional query words:

Keywords          : kbDirect3dRM KbDirectX500 kbDirectX600 kbDirectX500a kbDirectX520 
Hardware          : x86
Issue type        : kbprb

Last Reviewed: December 2, 1998