Based on your terrain, I implemented my own terrain and now I’m coding a triangle picker, that can see on which triangle of the terrain the mouse if going over.

But I’m stuck with this:
Is it possible to get the new positions of the vertices, that have been moved by the shader/effect?
My “triangle picker” works, but only with the old positions of the vertices.

Thanks in advance!

http://www.megaupload.com/?d=9IUCNV4V

It’s a XNA 4.0 version of this sample. Hope you guys can use it. Catalin, feel free to add this to your blog if you want, after all the code was yours to begin with .

Alex

in the grid.cs class replace:
draw()
{
Game.GraphicsDevice.SetVertexBuffer( vb );
Game.GraphicsDevice.Indices = ib;
Game.GraphicsDevice.DrawIndexedPrimitives( PrimitiveType.TriangleList, 0, 0, ( Dimension + 1 ) * ( Dimension + 1 ), 0, 2 * Dimension * Dimension );
}

and the:
public void LoadGraphicsContent()
{
vb = new VertexBuffer( Game.GraphicsDevice, VertexPositionNormalTexture.VertexDeclaration, ( Dimension + 1 ) * ( Dimension + 1 ), BufferUsage.None );
ib = new IndexBuffer( Game.GraphicsDevice, typeof(int), 6 * Dimension * Dimension, BufferUsage.None );
vb.SetData( vertices );
ib.SetData( indices );
}

And you should be good to go!

I could probably do a whole port, but I have no where to post it…

error 1: error X3000: syntax error: unexpected token ‘PixelShader’

solution : change the name of it to something else (and make sure to update the technique)

error 2 : XNA Framework HiDef profile does not support vertex texture format Color.

if you try to use Reach you will get this error: XNA Framework Reach profile does not support vertex shader model 3.0.

solution: right click height1.dds in the solution and select properties. Under ‘content processor’ change ‘Texture Format’ to NoChange. This is easier than Paul C’s solution.

To be honest, I only used the textures, grid.cs and .fx files in my code. So there could be other errors.

I made a quick method to do this, and it seems to work:

var OutTex = new Texture2D(GraphicsDevice, InTex.Width, InTex.Height, false, SurfaceFormat.Vector4);

Color[] In = new Color[InTex.Width * InTex.Height];
Vector4[] Out = new Vector4[InTex.Width * InTex.Height];
InTex.GetData(In);
for (int i = 0; i < InTex.Width * InTex.Height; i++)
Out[i] = new Vector4(In[i].R / 255f, In[i].G / 255f, In[i].B / 255f, In[i].A / 255f);
OutTex.SetData(Out);

return OutTex;

Thanks again Catalin for another great article, I've learn a ton from your site.

Warning 1 Member ‘Heightmap.Game1.LoadGraphicsContent(bool)’ overrides obsolete member ‘Microsoft.Xna.Framework.Game.LoadGraphicsContent(bool)’. Add the Obsolete attribute to ‘Heightmap.Game1.LoadGraphicsContent(bool)’.

Warning 2 Member ‘Heightmap.Game1.UnloadGraphicsContent(bool)’ overrides obsolete member ‘Microsoft.Xna.Framework.Game.UnloadGraphicsContent(bool)’. Add the Obsolete attribute to ‘Heightmap.Game1.UnloadGraphicsContent(bool)’.

Error 3 The name ‘ResourceUsage’ does not exist in the current context

Error 4 The name ‘ResourceManagementMode’ does not exist in the current context

Error 5 The name ‘ResourceUsage’ does not exist in the current context

Error 6 The name ‘ResourceManagementMode’ does not exist in the current context

Can you please tell me what I am missing ?