• Create Account

Old topic!

Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.

2 replies to this topic

### #1timothyjlaird  Members

599
Like
0Likes
Like

Posted 30 June 2012 - 01:49 PM

I'm trying to implement some simple water in XNA. Right now I'm focusing on the vertex shader part to generate at least passably realistic wave motion by manipulating the 'y' values of my grid. This is the code I'm using for the shader (time is gameTime.TotalGameTime.Milliseconds / 80)...

float4x4 xWorldViewProjection;
Texture xColoredTexture;
int time;
sampler ColoredTextureSampler = sampler_state
{
texture = <xColoredTexture>;
magfilter = LINEAR;
minfilter = LINEAR;
mipfilter = LINEAR;
};
struct VertexIn
{
float4 position : POSITION;
float2 textureCoordinates : TEXCOORD0;
};
struct VertexOut
{
float4 Position : POSITION;
float2 textureCoordinates : TEXCOORD0;
};
{
VertexOut Output = (VertexOut)0;
float sinarg = mul(input.position.x, 0.5) + time;
input.position.y = mul(0.5, sin(sinarg));
Output.Position = mul(input.position, xWorldViewProjection);
Output.textureCoordinates = input.textureCoordinates;
return Output;
}
{
float4 color;
color = tex2D(ColoredTextureSampler, input.textureCoordinates.xy);
return color;
}
technique Textured
{
pass Pass0
{
}
}


The problem is that sin waves only get me so far. Can someone point me in the direction of a better algorithm to calculate the y values for my verticies in my vertex shader? Preferably something that isn't too math heavy?

Short video of where I am right now:

### #2Jason Z  Members

6417
Like
1Likes
Like

Posted 01 July 2012 - 05:36 AM

You can grab my WaterSimulation demo from my Hieroglyph 3 engine here. It uses a navier stokes style solver to implement the water animation, and it currently runs in the compute shader. That won't work directly in XNA, but you could always move the solver portion to the CPU and just upload the height data to the GPU. Or you could modify it to run in the vertex shader using multiple passes - it all depends on what you are looking for.

If you have any questions about the implementation just let me know.

Jason Zink :: DirectX MVP

Direct3D 11 engine on CodePlex: Hieroglyph 3

Games: Lunar Rift

### #3timothyjlaird  Members

599
Like
0Likes
Like

Posted 01 July 2012 - 06:13 AM

You can grab my WaterSimulation demo from my Hieroglyph 3 engine here. It uses a navier stokes style solver to implement the water animation, and it currently runs in the compute shader. That won't work directly in XNA, but you could always move the solver portion to the CPU and just upload the height data to the GPU. Or you could modify it to run in the vertex shader using multiple passes - it all depends on what you are looking for.

If you have any questions about the implementation just let me know.

Thanks! This will take me a while to figure out but I appreciate the help.

Old topic!

Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.