View Full Version : vertex program & VBO problem - solved

09-24-2004, 03:45 AM
currently trying to get matrix palette skinnin to work, and while it works fine with regular Vertex Arrays, the moment I use VBOs it doesnt work

I use vertex program & vbo combo for particles as well and there it works...

here is what I do for particle:
- bind buffers
- stream particle data using subBuffer
- set up pointers (position, normal...)
- bind program
- submit 8 extras using glProgramLocalParameter4fARB
- enable program
- render

and this here for matrix palette skinning results into a crash when trying to draw (on ati it doesnt crash but nothing is visible)

- bind buffers
- stream data to buffer (the part using software skinning)
- set up pointers (attrib6)
- bind program
- submit 80 vectors for the matrices using glProgramLocalParameter4fARB
- enable program
- set up pointers (pos,normal,color)
- render

which results into a crash
funny thing is when I set vbo to STREAM it works like for 5 frames (I see nothing so) and then it crashes with "abnormal program termination"
when I use STATIC (and I dont submit the data of software skinner) it immediately crashes on the draw call givin a memory address error.

however the same setup works with vertex array

when I dont do the 80 glProgramLocal.. calls the app wont crash, but well the matrices not updated so I see nothing hehe

I know it likely aint efficient handing over so many vectors and such, but well for the moment I want to learn to make it work =)

09-24-2004, 03:56 AM
ha I made the order match now and it works... meanining in all the other cases I did right per luck hehe

- bind buffer
- pointers to all per vertex attribs
- bind program
- local params
- enable
- render

but why ?

09-24-2004, 07:49 AM
I don't see anything that's obviously out of spec. in your code... But I have a couple possible "pointers" ( :p ) to offer...

* Is the attrib6 array a member of the VBO?

I know NVIDIA drivers sometimes make a call to abort (...) [which is where an "abnormal program termination..." message comes from] somewhere when they run into a memory error.

This was VERY annoying in their VAR extension and it seems to have been carried over to their VBO implementation.

* Have you checked the error stack after every API call? If you do something out of order, the VBO/VP extensions are supposed to generate an INVALID_OPERATION/VALUE error.

09-24-2004, 01:00 PM
all per vertex data was in the vbo and pointed to when the vbo was bound

and indeed it threw a opengl error like 5 frames then the app crashed

the error strangely came up a tad later, ie not right after the draw call or before it...