I'm trying to implement GPU based geometry clipmapping and have problems to apply a simple heightmap to my terrain. For the heightmap I use a simple texture with the surface format "single". I've taken the texture from here. To apply it to my terrain, I use the following shader code: texture Heightmap; sampler2D HeightmapSampler = sampler_state { Texture = <Heightmap>; MinFilter = Point; MagFilter = Point; MipFilter = Point; AddressU = Mirror; AddressV = Mirror; }; Vertex Shader: float4 worldPos = mul(float4(pos.x,0.0f,pos.y, 1.0f), worldMatrix); float elevation = tex2Dlod(HeightmapSampler, float4(worldPos.x, worldPos.z,0,0)); worldPos.y = elevation * 128; The complete vertex shader (also containig clipmapping transforms) looks like this: float4x4 View : View; float4x4 Projection : Projection; float3 CameraPos : CameraPosition; float LODscale; //The LOD ring index 0:highest x:lowest float2 Position; //The position of the part in the world texture Heightmap; sampler2D HeightmapSampler = sampler_state { Texture = <Heightmap>; MinFilter = Point; MagFilter = Point; MipFilter = Point; AddressU = Mirror; AddressV = Mirror; }; //Accept only float2 because we extract 3rd dim out of Heightmap float4 wireframe_VS(float2 pos : POSITION) : POSITION{ float4x4 worldMatrix = float4x4( LODscale, 0, 0, 0, 0, LODscale, 0, 0, 0, 0, LODscale, 0, - Position.x * 64 * LODscale + CameraPos.x, 0, Position.y * 64 * LODscale + CameraPos.z, 1); float4 worldPos = mul(float4(pos.x,0.0f,pos.y, 1.0f), worldMatrix); float elevation = tex2Dlod(HeightmapSampler, float4(worldPos.x, worldPos.z,0,0)); worldPos.y = elevation * 128; float4 viewPos = mul(worldPos, View); float4 projPos = mul(viewPos, Projection); return projPos; }