How to implement multitextureing

How to implement multitextureing

EgyDev (guest) 09 Sep 2009 15:30

**Hi all I made a terrain through making an array of four point using VertexPositionColorTexture type and then use function drawuserprimitives and use trainglestrip technique to make the draw and here is the code

const float BOUNDARY = 160000;
VertexPositionColorTexture[] mVertGround = new VertexPositionColorTexture[4];
VertexDeclaration mVertPosColorTex=new VertexDeclaration(graphics.GraphicsDevice, VertexPositionColorTexture.VertexElements);
private void init_ground() //called in he intialize() method
{
Vector2 uv = new Vector2(0.0f, 0.0f);
Vector3 pos = new Vector3(0.0f, 0.0f, 0.0f);

// set for vertices of surface with uv, pos, and color data
uv.X = 24.0f; uv.Y = 24.0f; pos.X = -BOUNDARY; pos.Y = -10.0f; pos.Z = -BOUNDARY;
mVertGround[0] = new VertexPositionColorTexture(pos, Color.Green, uv); //front right
uv.X = 24.0f; uv.Y = 0.0f; pos.X = BOUNDARY; pos.Y = -10.0f; pos.Z = -BOUNDARY;
mVertGround[1] = new VertexPositionColorTexture(pos, Color.Red, uv); //back right
uv.X = 0.0f; uv.Y =24.0f; pos.X = -BOUNDARY; pos.Y = -10.0f; pos.Z = BOUNDARY;
mVertGround[2] = new VertexPositionColorTexture(pos, Color.Blue, uv); //front left
uv.X = 0.0f; uv.Y = 0.0f; pos.X = BOUNDARY; pos.Y = -10.0f; pos.Z = BOUNDARY;
mVertGround[3] = new VertexPositionColorTexture(pos, Color.White, uv); //back left
}
private void draw_ground() //called in the draw method
{

// 3: build cumulative world matrix using I.S.R.O.T. sequence
// identity, scale, rotate, orbit(translate & rotate), translate
mMatWorld = Matrix.Identity ;

// 4: pass wvp matrix to shader
mfxTex.Parameters["fx_WVP"].SetValue(mMatWorld * mMatView * mMatProj);
mfxTex.Parameters["fx_Texture"].SetValue(grass);
mfxTex.CommitChanges();

// 5: draw object - select vertex type, primitive type, # of primitives
graphics.GraphicsDevice.VertexDeclaration =mvertalaa;
graphics.GraphicsDevice.DrawUserPrimitives<VertexPositionColorTexture>(
PrimitiveType.TriangleStrip, mVertGround, 0, 2);
}

The question here is how can I implement multitextureing to this terrain

**

Re: How to implement multitextureing

rbwhitaker 09 Sep 2009 15:54

That's looking pretty good! Keep it up!

I'm virtually certain that the BasicEffect class cannot handle multi-texturing, but it looks like you already know that, since it looks like you've written your own effect.

There are a lot of ways you can go about this. My first thought, though, is that in your pixel shader, you can just sample from all of the textures you are interested in, and add up their values and return that for the color. Or, rather than just adding them up, add the values together, then divide by the total number of textures, so that you don't get over-saturated values.

Now, I haven't checked this code, but this would look something like this:

float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0
{
    float3 light = normalize(DiffuseLightDirection);
    float3 normal = normalize(input.Normal);
    float3 r = normalize(2 * dot(light, normal) * normal - light);
    float3 v = normalize(mul(normalize(ViewVector), World));
    float dotProduct = dot(r, v);
 
    float4 specular = SpecularIntensity * SpecularColor * max(pow(dotProduct, Shininess), 0) * length(input.Color);
 
    float4 textureColor1 = tex2D(textureSampler1, input.TextureCoordinate);
    float4 textureColor2 = tex2D(textureSampler2, input.TextureCoordinate);
 
    float totalTextures = 2;
    return saturate((textureColor1 + textureColor2) / totalTextures * (input.Color) + AmbientColor * AmbientIntensity + specular);
}

You could even go a step further and have a third texture that determines how much each of the textures are visible at a particular point. So, for example, you could have three textures. The first is a grass texture, the second is a dirt texture, and the third is a grayscale image that shows where the output should show grass (colored white) and where it should show dirt (colored black) and where it should show a combination of dirt and grass (some gray color). With this, you would have to pass over three textures, so it might get a bit hairy, but I'd imagine it would give some pretty nice results.

Once again, I haven't checked this code, but something like this should work:

float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0
{
    float3 light = normalize(DiffuseLightDirection);
    float3 normal = normalize(input.Normal);
    float3 r = normalize(2 * dot(light, normal) * normal - light);
    float3 v = normalize(mul(normalize(ViewVector), World));
    float dotProduct = dot(r, v);
 
    float4 specular = SpecularIntensity * SpecularColor * max(pow(dotProduct, Shininess), 0) * length(input.Color);
 
    float4 textureColor1 = tex2D(textureSampler1, input.TextureCoordinate);
    float4 textureColor2 = tex2D(textureSampler2, input.TextureCoordinate);
    float4 textureCombination = tex2D(textureSampler3, input.TextureCoordinate);
    float combinationAmount = (textureCombination.x + textureCombination.y + textureCombination.z) / 3;
 
    float4 finalTextureColor = textureColor1 * combinationAmount + textureColor2 * (1 - combinationAmount);
    return saturate(finalTextureColor * (input.Color) + AmbientColor * AmbientIntensity + specular);
}

Re: How to implement multitextureing

EgyDev (guest) 23 Sep 2009 18:01

Thank you so much but can you give me the whole effect file

Re: How to implement multitextureing

EgyDev (guest) 24 Sep 2009 04:58

Thank you so much it worked with me but I have a big problem which is tilinig please just look at this image where I implemented multitextureingTo refer to an image attached to a page, use pagename/filename

Re: How to implement multitextureing

EgyDev (guest) 24 Sep 2009 05:07

Iam so sorry here is the link of the image http://img97.imageshack.us/img97/9498/problemp.jpg

Re: How to implement multitextureing

EgyDev (guest) 24 Sep 2009 05:17

Iam so sorry here is the image

Re: How to implement multitextureing

EgyDev (guest) 25 Sep 2009 03:28

What if I created another terrain using the same code (in the first post in this thread) how can I omit the boundaries between 2 terrains I mean how to mix the two terrain so that the player fell that this is only one terrain or in other meaning how can I omit this straight line between 2 terrains