Brain bender, part two: Motion blur.

[Zero]

Alright, rocket scientists. For an effect in a game I'm writing I want to use a motion blur effect on a bitmap. I'd also like it to be done on the fly, so I don't need to carry around 400 640x480 bitmaps with my program.

I was thinking of an effect similar to the motion blur in PC Paintbrush or Corel PhotoPaint. All of these effects are on a straight black background, so we don't need to worry about blending in backgrounds or sprite transparencies.

Something tells me I'm going to do a lot of pixel plinking here. Does anyone know a good algorithm, or does anyone know of a site that deals with this sort of thing?

Thanks,
~Zero the Inestimable

[Arbiter]

Couldn't you use BitBlt and paint the image a couple of pixels offset using one of the operators (vbsrcwibble etc)

Whatever you're going to do - it's going to be slow...

[Nirces]

Depends on how real you want it

You might be able to get away with drawing the image tice, overlapping them mostly, so you get the image echo, then Drawing a standard Motion Blur Image, An Image with Black Lines graded into white, with white being transparent.

If you apply a mask to get the black lines then apply the mask of the Image your coping it over you should get a nice motion blur effect.

[Zero]

I should write a DLL with an API call that uses the parameter "VbSrcWibble"... I don't know what it would do, though.

I did a bunch of research on the web today. The results were not promising. I think I'm just going to limit myself to 30 frames and use a whole bunch o' prerendered JPEGs for my effects. I only need to blur three things ("Title", "How To Play", and "Game Over") so I might be able to get away with it.

Something tells me this one ain't gonna fit on one disk...

~Zero the Inestimable

[Zaei]

Something tells me this one ain't gonna fit on one disk...

No VB6 app will...

Z.

[Fox]

No VB6 app will...

welllllll.... if you're zipping MSVBVM60.DLL and put your exe on the disk it will fit

Erm.. 2 cents you know

[Zero]

I use VB 5. Yeah, I know, I'm primitive.

I usually keep the application on one disk and then hand out SFX archives of the VB5 runtimes as needed. I can stuff all of the runtimes (including various OCX files) on one disk if I use a RAR archive. I also provide a link to a download for the runtimes in the documentation. So far the system has worked...

I actually managed to stuff Gen and the VB5 runtimes on one disk once. Don't ask me how, though.

Hey, here's another one: If I use Jpegs instead of bitmaps in a picturebox and compile the application, do the Jpegs take up less space than the same images as bitmaps would, or does stupid VB just convert them to bitmaps anyway?

~Zero the Inestimable

[DNA7433]

from what i've heard, every image in a picturebox is converted to bitmap

[Jotaf98]

Well, to make motion blur, all you need to do is blt the object at another position, and then blend it with the front DC (or surface or whatever) each frame. That's how they do it.

I made a module with functions for this a while ago... you'll find it at http://161.58.186.97/showthread.php?s=&threadid=71234

[Zero]

Nope. They stay JPEGs. This changes everything... I just knocked my compiled EXE down from 2 megs to 312 KB.

~Zero the Inestimable

[kedaman]

operating a jpeg in memory is much slower than with bitmaps.
i think motion blur is done by looping and keep adding to a carrying variable and then multiplying it with a motion blur index and then finally assigning carry to current pixel.