Screen Shot and Question

Screen Shot

Just got an X50v, running Vincent and UG. Was wondering why the heck the squares look concave at certain angles?

We are using ambient and diffuse light, both red. The materials are obviously either reflecting red or black.

We are using calls to DrawElement with an indexed cube… We followed ZeusCMD’s tutorials, and we are confused as to this graphical glitch.

Anyone experience anything similar?

We tried altering the front clipping plane, but with no progress.

Also note we are starting on our own Widget system, with CheckBoxes, Scrollable TextBoxes, IconButtons, and TextButtons. We are also working (slowly) on our own model loader. Finally, using the image from the DancingFlora demo, we made our own TextRenderer.

[ April 26, 2005: Message edited by: 3DChess_Developer ]

I can’t help wondering why you’re using a software renderer (Vincent) when the X50v supports hardware rendering?

Because I didn’t know about PowerVR before last week (and had no PocketPC). I’ll do the transition sometime soon.

PowerVR also needs better code samples, the ones on the SDK are too complex for beginners.

Here’s my guess: Vincent uses piecewise linear interpolation of texture coordinates between perspectively correct mapped coordinates. The size of the interval is actually a configuration parameter when you recompile the library.

Otherwise, I’d also propose moving to the hardware renderer for this device.

  • HM

<BLOCKQUOTE><font size=“1” face=“Arial, Verdana, Helvetica, sans-serif”>quote:</font><HR>Originally posted by 3DChess_Developer:
PowerVR also needs better code samples, the ones on the SDK are too complex for beginners.<HR></BLOCKQUOTE>

I have to endorse this statement strongly; although the SDK is aimed at experienced developers, it should really contain some basic examples (simple primitives not wrapped in algorithms, etc, a la Red book) to help folks get going, particularly those new to programming for mobile devices. Someone experienced with preparing documentation needs to go through the acccompanying docs to produce at least one doc that gives a clear overview of the API and extensions. That’s if one wants to make this more accessible.

I would love to put this topic to rest, but I am getting questiona bout it for the game’s postmortem… Can anyone tell me why my squares were curved?? HM-Will said because of interpolation of texture coords, but that example had no texturing enabled… I need an answer, and can’t find one!!!


Thanks in advance!!!

You’ll need to post a better shot, do you have a pixel for pixel screen capture instead of a fuzzy out of focus webcam image?

Initially I thought it could have been roping on antialiased pixels but that makes no sense because it’s aligned with the board. I think the polygons you’ve drawn may actually be subdivided and concave on one axis perhaps to mitigate zfighting with the chess pieces and the board.

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