I use GeoMipTerrain with my terrain shader (from panda3d forum).
Shader file like this:
//Cg
//Cg profile arbvp1 arbfp1
// shader loosely based on pro-rsoft's from the panda3d forums
// shader assumes 6 texture stages:
// 0-2 textures
// 3-5 alpha maps
// vertex shader accepts unit 0 and 3 texture coords as input
// and outputs unit 0 scaled and unit 3 unchanged
// fragment shader uses unit 0 coordinates to access textures
// and unit 3 coordinates (un-scaled) to access alpha maps
// gsk, june-2008
void vshader( in float4 vtx_position : POSITION,
in float3 vtx_normal : NORMAL,
in float2 vtx_texcoord0 : TEXCOORD0,
in float2 vtx_texcoord3 : TEXCOORD3,
in uniform float4x4 mat_modelproj,
in uniform float4 k_lightvec,
in uniform float4 k_lightcolor,
in uniform float4 k_ambientlight,
in uniform float4 k_tscale,
out float l_brightness,
out float2 l_texcoord0 : TEXCOORD0,
out float2 l_texcoord3 : TEXCOORD3,
out float4 l_position : POSITION)
{
l_position=mul(mat_modelproj,vtx_position);
l_texcoord0=vtx_texcoord0*k_tscale;
l_texcoord3=vtx_texcoord3;
// lighting
float3 N = normalize( vtx_normal );
float3 L = normalize( k_lightvec.xyz );
l_brightness = (max( dot( -N, L ), 0.0f )*k_lightcolor)+k_ambientlight;
}
void fshader( in float4 l_position : POSITION,
in float2 l_texcoord0 : TEXCOORD0,
in float2 l_texcoord3 : TEXCOORD3,
in float l_brightness,
in uniform sampler2D tex_0 : TEXUNIT0,
in uniform sampler2D tex_1 : TEXUNIT1,
in uniform sampler2D tex_2 : TEXUNIT2,
in uniform sampler2D tex_3 : TEXUNIT3,
in uniform sampler2D tex_4 : TEXUNIT4,
in uniform sampler2D tex_5 : TEXUNIT5,
out float4 o_color : COLOR )
{
float4 tex1=tex2D(tex_0,l_texcoord0);
float4 tex2=tex2D(tex_1,l_texcoord0);
float4 tex3=tex2D(tex_2,l_texcoord0);
float alpha1=tex2D(tex_3,l_texcoord3).z;
float alpha2=tex2D(tex_4,l_texcoord3).z;
float alpha3=tex2D(tex_5,l_texcoord3).z;
o_color =tex1*alpha1;
o_color+=tex2*alpha2;
o_color+=tex3*alpha3;
o_color=o_color*(l_brightness);
o_color.a=1.0;
}
I think vtx_normal is the same for all vertex. How to fix it? [/img]