Snow and Rain Effects

[WILL]

Thanks Will, I like the way the snow builds up on the ground

np Actually over time it starts to look a bit... toothy. I'd normalize the ground layer every X particle of snow that hits to smoothen it out a bit more... I've never really experimented with it much, but it's something to look at...

[Wizard]

Will, I implimented your snow demo into my game and everything works as I want it to. Except for the fps dropping from 200 fps to around 50... I checked your demo and it runs at around 16 fps...So my question is: Does the particle system as a rule eat up the fps or do you think it could be something else? I checked and rechecked my code.

[WILL]

Will, I implimented your snow demo into my game and everything works as I want it to. Except for the fps dropping from 200 fps to around 50... I checked your demo and it runs at around 16 fps...So my question is: Does the particle system as a rule eat up the fps or do you think it could be something else? I checked and rechecked my code.

Before I say something else, how many particles are you using?

[Wizard]

The same as in your demo MAX_SNOW = 500. What I did change is the screen_height & screen_width. And you're right when i decrease the Max_Snow the fps increases, but then it doesn't look so dense...

[WILL]

I'm not entirely convinced that it's the number of pixels --I mean I could probably spit out about 2000 in OpenGL without breaking a sweat-- but, I do remember that DelphiX used to access video memory rather slowly so...

[Wizard]

No problem, thanks anyway

[NecroDOME]

About speed, if you use instancing within DirectX you can spit out 20k without breaking sweat. And it's not that hard to accomplish!

[Wizard]

This is the 1st time I hear about instancing within DirectX. Must I have a look at clooties translations or do you have a sample?

[NecroDOME]

msdn (DirectX SDK) has a nice example http://msdn.microsoft.com/en-us/library/bb174602(VS.85).aspx
If you take a look at Constants Instancing and Shader Instancing the differences are really small. You don't need to do extra-fancy stuff.

[Wizard]

I found a solution to the speed problem I had once I introduced snow in my game.

Instead of

DXImageList.Items[9].Draw(DXDrawGame.Surface,0,0,0);

use

DxdrawGame.Surface.BltFast(0, 0, BackImage.ClientRect,1, BackImage);

bltFast increased the fps to what it is set at in my game, which is 200 fps

btw using BLTFast drawing only works if the image being drawn is exactly the same as clientHeight and clientWidth, if it overlaps it will not work