CompuServe Messages

#PAR errors

    15-Oct-94 12:30:23
Sb: #129180-#PAR errors
Fm: Gus Grubba 70673,1605
To: David M. Taffet 73733,1452
Ok, first of all, there is no such thing as a PAR driver for 3D Studio. There is no difference whatsoever saving a Targa file from 3D Studio or from the command prompt. All 3D Studio does is to create a targa file on what it thinks is a DOS drive. The same is the case when you simply COPY it from the command prompt. What causes an animation to go berserk as you describe is lack of throughput from your PAR disk. If your PAR disk can pump 3 megabytes a second and 30 frames worth of video is more than that, the PAR hardware will get lost. That's what the Block Limit is all about. Run PARTEST and check what's the throughput of your PAR system. It will give you a number between 2 and 3.5 megabytes/second. Divide that by 30 (frames). Let's assume you had an even 3meg/sec. That gives 3,145,738 / 30 = 104,857. That means your frame size limit is 104,857 bytes. Each PAR block is 512 bytes long. If we divide the frame limit by the block size we get the block limit. That is, 104,857 / 512 = 205. In this scenario, if you have the block limit set to anything greater than 205 it will blow up just like you described. Also note that the throughput decreases as you move into the disk. That is, if you have a lot of stuff on your PAR disk, the block limit will reduce for the animations at the end (closer to the center of the disk). That's why PARTEST gives you a throughput check for the entire media. Check what you got at the beginning of the disk and than check what is like at the end. If you plan on creating humongous animations or if you are about to create one on a disk rather full, you should calculate a new block limit accordingly. Home work: Go and check what's you block limit is set for. Run PARTEST and let me know what's the throughput of your PAR disk (beginning of the disk and end).