Can you help ? I'm working on putting multiple textures tiled onto a single mesh. The reason for this is I have 10km square terrain meshes that need to be overlaid by map rasters. Initially I downgraded the 4000x4000 images to 1024x1024 but the degredation was pretty awful, and now want to render 4 tiled quadrants of the raster tother on a single 10km mesh. (1024 being a common maximum tex size, and this isn't simulated landscape but real maps). Why not just reduce the mesh size ? Like most terrain stuff I made a design choice to "clamp" the edges of the mesh tiles during simplification to prevent tearing, and the "edge to non-edge" ratio of vertexes makes 10km nice and accurate, whereas a solution involving a 5km mesh had "too much edge" and oversimplified the centre. Thats where I am ; my problem is that I intended to render all four textures in a single pass by using four sets of Tex Coords on the mesh - which works fine in principle. I set the following (some not duplicated for brevity, sample of two of the four here) -- Start of code device.SamplerState[0].AddressU = TextureAddress.Border; device.SamplerState[0].AddressV = TextureAddress.Border; device.SamplerState[1].AddressU = TextureAddress.Border; device.SamplerState[1].AddressV = TextureAddress.Border; device.SamplerState[0].BorderColor = Color.Transparent; device.SamplerState[1].BorderColor = Color.Transparent; device.TextureState[0].ColorOperation = TextureOperation.Modulate; device.TextureState[0].ColorArgument1 = TextureArgument.TextureColor; device.TextureState[0].ColorArgument2 = TextureArgument.Diffuse; device.TextureState[0].AlphaOperation = TextureOperation.SelectArg1; device.TextureState[0].AlphaArgument1 = TextureArgument.TextureColor; device.TextureState[1].ColorOperation = TextureOperation.Modulate; device.TextureState[1].ColorArgument1 = TextureArgument.TextureColor ; device.TextureState[1].ColorArgument2 = TextureArgument.Diffuse; device.TextureState[1].AlphaOperation = TextureOperation.SelectArg1; device.TextureState[1].AlphaArgument1 = TextureArgument.TextureColor; device.SetTextureStageState(0,TextureStageStates.TextureCoordinateIndex,1); device.SetTexture(0,this.highResolutionTextures[0]); device.SetTextureStageState(1,TextureStageStates.TextureCoordinateIndex,2); device.SetTexture(1,this.highResolutionTextures[1]); -- then render mesh. -- End of code Unfortunately the outcome of this (which I understand conceptually) is that the border color of transparent is in effect overwriting the previous texture stage so I only ever see the last texture stage. The Color.Transparent overwrites the underlying texture stage. I think my understanding of how the Texture stage merges the previous Alpha value isn't correct (other areas of the app where multiple textures are overlaid work fine - its just that the 'border color' doesn't seem to be counted as part of the output from the stage ... or something). I cant see a way out of this, can anyone help ? How would you render more than one non-overlapping texture on a single mesh ? Thanks, Phillip

Gulgi,

Brilliant, thanks. Just the nudge I needed to get me there. For reference to the site, the correct sequence and settings for tiling multiple different textures on a single mesh (in my case quadrants) is;

-- Start of code
device.SamplerState[0].AddressU = TextureAddress.Border;
device.SamplerState[0].AddressV = TextureAddress.Border;
device.SamplerState[1].AddressU = TextureAddress.Border;
device.SamplerState[1].AddressV = TextureAddress.Border;
device.SamplerState[2].AddressU = TextureAddress.Border;
device.SamplerState[2].AddressV = TextureAddress.Border;
device.SamplerState[3].AddressU = TextureAddress.Border;
device.SamplerState[3].AddressV = TextureAddress.Border;

device.SamplerState[0].BorderColor = Color.Transparent;
device.SamplerState[1].BorderColor = Color.Transparent;
device.SamplerState[2].BorderColor = Color.Transparent;
device.SamplerState[3].BorderColor = Color.Transparent;

device.TextureState[0].ColorOperation = TextureOperation.Modulate;
device.TextureState[0].ColorArgument1 = TextureArgument.TextureColor;
device.TextureState[0].ColorArgument2 = TextureArgument.Diffuse;
device.TextureState[0].AlphaOperation = TextureOperation.SelectArg1;
device.TextureState[0].AlphaArgument1 = TextureArgument.TextureColor;

device.TextureState[1].ColorOperation = TextureOperation.Modulate;
device.TextureState[1].ColorArgument1 = TextureArgument.Current ;
device.TextureState[1].ColorArgument2 = TextureArgument.TextureColor;
device.TextureState[1].AlphaOperation = TextureOperation.SelectArg1;
device.TextureState[1].AlphaArgument1 = TextureArgument.Diffuse;

device.TextureState[2].ColorOperation = TextureOperation.Modulate;
device.TextureState[2].ColorArgument1 = TextureArgument.Current ;
device.TextureState[2].ColorArgument2 = TextureArgument.TextureColor;
device.TextureState[2].AlphaOperation = TextureOperation.SelectArg1;
device.TextureState[2].AlphaArgument1 = TextureArgument.Diffuse;

device.TextureState[3].ColorOperation = TextureOperation.Modulate;
device.TextureState[3].ColorArgument1 = TextureArgument.Current ;
device.TextureState[3].ColorArgument2 = TextureArgument.TextureColor;
device.TextureState[3].AlphaOperation = TextureOperation.SelectArg1;
device.TextureState[3].AlphaArgument1 = TextureArgument.Diffuse;

// Note the first TU/TV pair in my FVF refer to another texture stage.
device.SetTextureStageState(0,TextureStageStates.TextureCoordinateIndex,1);
device.SetTexture(0,this.highResolutionTextures[0]);
device.SetTextureStageState(1,TextureStageStates.TextureCoordinateIndex,2);
device.SetTexture(1,this.highResolutionTextures[1]);
device.SetTextureStageState(2,TextureStageStates.TextureCoordinateIndex,3);
device.SetTexture(2,this.highResolutionTextures[3]);
device.SetTextureStageState(3,TextureStageStates.TextureCoordinateIndex,4);
device.SetTexture(3,this.highResolutionTextures[2]);

-- End of code

Just one further question ; is setting the SampleState an expensive operation on a per-frame basis (I've bunched all my code up in the above sample for clarify), or should I set it only once in the app ?

Phillip