I''ve been tracking a "weird" problem for about two weeks. Using DirectX 9, I nad several instances where a back buffer would not present to the screen after the primitives were rendered. It appeared like a timing issue since I could get the missing primitives to display if I "refreshed" the screen through an application mechanism. I''m using an NVidia TNT2 card; I have updated the drivers to the latest; I updated the DirectX SDK to the "summer" version; the device is created as D3DDEVTYPE_HAL. Yet, the problem(s) remained. For no apparent reason, I toned down the Hardware acceleration in Windows display properties applet to a setting that says "Disable all DirectDraw and Direct3D accelerations....". Now, the display problems no longer exist. What gives? Have I sacrificed performance to solve a problem? Gort...Klaatu, Barada Nikto!

What flags do you create your vertex buffer with?

See below for snippet:

// Create the vertex buffer.
if( FAILED(pDirect3DDevice->CreateVertexBuffer(
numverts*sizeof(CUSTOMVERTEX), // length
D3DUSAGE_SOFTWAREPROCESSING | D3DUSAGE_WRITEONLY,// usage
D3DFVF_CUSTOMVERTEX, // vertex format
D3DPOOL_DEFAULT, // memory class
&pDirect3DVb, // ptr to intf.
NULL))) // reserved


Gort...Klaatu, Barada Nikto!

quote:Original post by Klaatu
I''ve been tracking a "weird" problem for about two weeks. Using DirectX 9, I nad several instances where a back buffer would not present to the screen after the primitives were rendered. It appeared like a timing issue since I could get the missing primitives to display if I "refreshed" the screen through an application mechanism.

Just to make sure I understand: The back-buffer isn''t presented at all (i.e. the frame is skipped) or the presentation is delayed until you force it in some way?

Muhammad Haggag

As best I can tell, the frame is presented but never appears on the screen. To debug this, I created a function that would build a bitmap of the back buffer an instant before the Present() method is called. The bitmap contains a perfect image. The image, however, never makes it to the screen. I can force it to the screen with another function that basically recreates the image via a toolbar button. It''s almost like the I/O is getting blocked for some reason. And as I said, the problem disappears if I turn down the hardware acceleration within Windows XP.

Gort...Klaatu, Barada Nikto!