EASTFIST

If you can’t implement real 3D, then fake 2D 3D graphics might work.

UPDATE Apr. 9, 2013 – Looky, looky, success!

This is real 3D rotation transformations using QTransform and QPainter. No third-party 3D library reference to OpenGL or DirectX. That means it has a higher chance of working across different operating systems (assuming Qt is cooperative).

UPDATE Aug. 10, 2012 – Here’s how you use Qt’s QTransform on a paint device for “true” 3D transformations.

Sub-classing your widget’s PaintEvent:

void MainWidget::paintEvent(PaintEvent e)
{
    int rotationAngle = 45;
    QPixmap pixmap("somefile.jpg");
    QTransform transform;

    //you need to translate it to the center of the
    //viewport because the default origin of
    //transformation (0,0) the top-left of the screen
    transform.translate(this.width()/2,this/height()/2);

    transform.rotate(rotationAngle,Qt::XAxis);

    //then you have to change it back
    transform.translate(-this.width()/2,-this/height()/2);

    QPainter painter(this);
    pntr.setTransform(transform);
    pntr.drawPixmap(QRect(0,0,320,240),pixmap);
    pntr.resetTransform();
    pntr.end();
}

———————————————

Back in the Super Nintendo (SNES) days, we enjoyed some pretty rad “fake” 3D games like F-Zero and Mario Kart. SNES had “mode 7”. Now that I’m developing my own 2D game engine, I really want to implement at the least some parallax for my backgrounds. While I’m sure I could accomplish this with OpenGL or DirectX, I don’t want to rely on anymore external DLL dependencies unless I need to. Qt provides a QTransform function, but it’s not quite there. I’ve been playing around with it.

In order to complete a full illusion of 3D, I’ll have to implement many separate buffers and composite those onto a final output buffer. Animation is just a bunch of output buffers played really fast to give you the illusion of movement.

I was able to produce the mock-up in Photoshop, which seems to have the perspective algorithm down. Now, it’s just a matter of figuring it out on my end for my Qt/c++ implementation.

Tags: 2d, 3d, concept, development, fake 3d, game, howto, mode 7, nintendo, nokia, programming, qt, snes, test

This entry was posted on Thursday, January 19th, 2012 at 3:32 am and is filed under My Artistic Endeavors, Technology. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.