After a long period of silence nesnausk! releases another demo - Zenit. Check it out. This is actually almost a one-man show: the concept, modeling, animations and code was done by Paulius. I did see how the real camera looks like when fully disassembled into almost 500 parts - it’s scary!

Ah… makes me want to do some demo again. Maybe someday!

I have added a small article on transformation matrices - what the values in the matrix really mean. The values are coordinate system axes of course, so if you know that already, just skip it.

Ok, I got an USB memory stick (PQI something). Now it has two partitions on it by default, one of them to store some sort of “USB Notebook” data. I am pretty sure I really don’t need that, so I was looking around for a way to merge those partitions. I ran this “USB Notebook” application in a hope that setup wizard will let me choose “no thanks, I don’t need this stuff”. Of course, it does not have such an option.

Pressing Cancel somewhere in there results in this dialog:

Pretty cool, I must say. Some advice I’d like to give for the application developers, if I may:

• Instead of trying to copy Aqua’s GUI, make the application actually do useful things. “I don’t need your stuff, please give me a single partition” is a pretty common use case. And please don’t make error messages like that be the topmost windows (now it stays on top even when I switch to another app).

• Either get someone to write English messages, or leave the message as is and change the caption to “All your base are belong to us”. For such an exciting error message I’d also change the button text to “YES!!!”. Let the user enjoy your software!

From the software manual: “Thanks a lot to you that are use our company’s product”. Gee, thank you that you are use your software on me!

For no good reason at all I moved my blog from Blogspot site to Wordpress here on my website. Things may be broken!

Also updated the dezign of the website & blog. Colors are for wimps, grayscale for the win!

OpenGL vertex buffer functionality, I mock thee too! Why couldn’t they make the specification simple&clear, and then why can’t the implementations work as expected?

It started out like this: converting some existing code that generates geometry on the fly. It used to generate that into in-memory arrays and then Just Draw Them. Probably not the most optimal solution, but that’s fine. Of course we can optimize that, right?

So with all my knowledge how things used to work in D3D I start “I’ll just do the same in OpenGL” adventure. Create a single big dynamic vertex buffer, a single big dynamic element buffer; update small portions of it with glBufferSubData, “discard” it (=glBufferData with null pointer) when the end is reached, rinse & repeat.

Now, let’s for a moment ignore the fact that updating portions of index buffer does not actually work on Mac OS X… Everything else is fine and it actually works! Except for… it’s quite a lot slower than just doing the old “render from memory” thing. Ok, must be some OS X specific thing… Nope, on a Windows box with GeForce 6800GT it is still slower.

Now, there are three things that could have gone wrong: 1) I did something stupid (quite likely), 2) VBOs for dynamically updated chunks of geometry suck (could be… they don’t have a way to update just one chunk without one extra memory copy at least), 3) both me and VBOs are stupid. If I was me I’d bet on the third option.

What I don’t get is: D3D has had a buffer model that is simple to understand and actually works for, like, 6 years now! Why ARB_vertex_buffer_object guys couldn’t just copy that? The world would be a better place! No, instead they make a way to map only whole buffer; updating chunks is extra memory copy; there are confusing usage parameters (when should I use STREAM and when DYNAMIC?); performance costs are unclear (when is glBufferSubData faster than glMapBuffer?) etc. And in the end when an OpenGL noob like me tries to actually make them work - he can’t! It’s slow!