42 replies to this topic

[TheSnidr]

• Title: Ripple Engine
• Description: Ripples the screen and makes it look like a flag or underwater.
• GM Version: GM7
• Registered: Yes
• File Type: .gmk
• File Size: 22Kb
• File Link:
  Flag ripple, at Host-a
  Water ripple, at Host-a

Additional Info
Someone asked how to make a flag flap in the wind without animating it in the Novice and Intermediate Users, and when I made this example, I thought it might also be useful to others.
There are two scripts, one for making flags (ripples are growing as they move to the right), and one for other effects, like a fullscreen ripple effect.
Here's the flag script:

/*draw_flag(texture_index,x,y,width,height,number_of_vertexes,waveheight,speed,intensity)Draws a texture with ripples like a flag."waveheight" defines how high the waves are, "speed" decides the speedof the waves, and intensity decides the number of waves.Script made by TheSnidr[url="http://thesnidr.blog.com/"]http://thesnidr.blog.com/[/url]*/var xtex,ytex,xx,xx1,xx2,yy,i,col,var1,var2,var3,c_dark;xtex=texture_get_width(argument0)ytex=texture_get_height(argument0)ripple=argument7*(-current_time/1000)*(room_speed/30)draw_primitive_begin_texture(pr_trianglestrip,argument0)for (i=0;i<=argument5;i+=1){    var1=i/argument5    var2=ripple+var1*argument8    var3=argument6*var1    xx=argument1+argument3*var1    xx1=xx+sin(var2)*var3    xx2=xx+cos(var2)*var3    yy=sin(var2)*var3    _xtex=var1*xtex    if cos(var2)>0 then col=200 else col=200+55*abs(cos(var2))    draw_vertex_texture_color(xx1,argument2+yy,_xtex,0,make_color_rgb(col,col,col),1)    draw_vertex_texture_color(xx2,argument2+yy+argument4,_xtex,ytex,make_color_rgb(col,col,col),1)}draw_primitive_end()

Thanks to GamerXP for better color gradients

Here's an example:

Edited by TheSnidr, 16 November 2010 - 09:54 PM.

[xot]

There is a bug in the download version. In the script there is a variable called "ripple_intensity" which is set to argument8. It should be "ripple_quality".

[Nocturne]

Yeah, I noticed that too... And state that if it´s less than 2 it won´t draw right! I found 6-10 to be a good level... Oh and it´s a rather nice effect, by the way!!!

[TheSnidr]

Fixed the bug. I have a habit of renaming some of the variables, but not all, before I put it out

The intensity, speed and waveheight arguments can be changed to make different kinds of weather. With high intensity, high speed and low waveheight, it will look like a swift breeze.
Low intensity (should normally not be below 5 or 6), high waveheight and a medium speed gives a stormy look.
A low intensity, medium waveheight and high speed makes it look like a strong gust of wind is blowing.

Try to experiment with the values yourself!

[Ruzzinator]

That is a very very nice effect!
Well done indeed!

It was lots 'o fun playing around making the speed really high or low etc
Good work!!

[wiiowner]

This looks very nice and the addition of self shadowing on the flag makes it that much better. 10/10! Also I didn't really mess around with the variables but it looks great and I don't think you would need to in any practical case. Just the amount of wind. Anyway great work.

[Fede-lasse]

I may guess that sin() is somewhat the creator of the basic waves?

Edited by Fede-lasse, 19 March 2009 - 02:35 PM.

[TheSnidr]

I may guess that sin() is somewhat the creator of the basic waves?

By the way, the shadow effect on the flag doesn't look 100% realistic.

Correct. And when multiplied with i (as in the for loop), the left part of the flag stands still, while the waves get bigger and bigger the further they get to the right.

I know the shadows look a little bit strange, but the only way I can think of to make it look better, is making more vertexes to the primitive.

[theweirdn8]

Thank you sooo m uch!
Ample LEgacy needed this badly.

[NickToony]

If this had the ability to use image_angle, I would absolutely love you.

[xot]

If this had the ability to use image_angle, I would absolutely love you.

If you mean you want to draw it in a direction other than horizontal, use a d3d transform before calling it:

d3d_transform_stack_push();
d3d_transform_add_rotation_z(angle);
d3d_transform_add_translation(x,y,0);
scr_draw_flag(sprite_index,0,0,0,300,150,wind,5,20);
d3d_transform_stack_pop();

[snowyowl]

That works? I thought you had to call d3d_start() first.

[Schreib]

My friendzzzz... xot shows his d3d_transform h4xx0rz. Oh, yeah, maybe it didn't originate from you, xot, but I still thank you for it.

[xot]

That works? I thought you had to call d3d_start() first.

Most of the d3d functions work without having to call d3d_start() first. As far as I know, the d3d_start() function is really only needed to enable the perspective projection and the depth buffer.

[Glen]

This is very useful. I appreciate you making this.

[klear]

Really great work.

[dadio]

Another very slick effect!
Damn, you seem to be the Master of "sin" use!

This could come in very useful!
The ability to customise "the strength of the wind" is really really nice!
Thanks for sharing!

[Fede-lasse]

Another very slick effect!
Damn, you seem to be the Master of "sin" use!

This could come in very useful!
The ability to customise "the strength of the wind" is really really nice!
Thanks for sharing!

My best guess would be that he was either bored or has just learned it in school lately.

Edited by Fede-lasse, 17 April 2009 - 08:46 PM.

[snabelost]

This is VERY useful if your making a quality game and need a good goal flar or something and this code is awsome, if it just had a little blur into it it would be awsome
(I added the blur code to it and used it in my game, ill upload code later )

[TheSnidr]

Thansk for nice comments everyone!

As I just saw my topic on top again, I felt like updating it a little.

I have removed most of the "ripple_" variables, and I now use the arguments directly.
I made the variables so that other people could see what is what, and where it is used, but it seems it worked against its purpose: it only became harder to read.

And also, the script now requires a texture index, instead of a sprite index. That means you can now also use a background, if you get its texture index first (through background_get_texture)