美术那边需要一个能在3dmax里用的支持diffuse纹理和顶点色的additive shader（不带光照）。
以前没搞过这个，于是从3dmax自带的vertexcolor.fx,DiffuseBump.fx拼凑出了一个，如下：
//-----------------------------DiffuseMapVertexcolorAdditive.fx
// 3ds max effect file
// Simple vertex color - work with the Vertex Paint tool. The max effect parser
// allows you to define any arbitary map channel to be passed in via a texcoord.
// In this case we are interested in Vertex Color, Illumination and Alpha which
// are stored in 0,-1,-2 respectively.
// light direction (view space)
// transformations
float4x4 World : WORLD;
float4x4 View : VIEW;
float4x4 Projection : PROJECTION;
float4x4 WorldViewProj : WORLDVIEWPROJ;
float4x4 WorldView : WORLDVIEW;
texture diffuseTexture : DiffuseMap<
string name = "seafloor.dds";
string UIName = "Diffuse Texture";
int Texcoord = 0;
int MapChannel = 1;
>;
int texcoord1 : Texcoord
<
int Texcoord = 1;
int MapChannel = 0;
>;
int texcoord2 : Texcoord
<
int Texcoord = 2;
int MapChannel = -2;
>;
struct AppData
{
float3 Pos : POSITION;
float2 TexCoord : TEXCOORD0;
float3 col : TEXCOORD1;
float3 alpha :TEXCOORD2;
};
struct v2f
{
float4 Pos : POSITION;
float4 color : COLOR;
float2 TexCoord0 : TEXCOORD0;
};
struct f2fb {
float4 col : COLOR;
};
v2f VS(
AppData IN
)
{
v2f Out = (v2f)0;
Out.Pos = mul(float4(IN.Pos,1),WorldViewProj); // position (projected)
float4 diff;
diff = float4(IN.col,1);
Out.color = diff;
Out.color.a = IN.alpha.x;
Out.TexCoord0.xy = IN.TexCoord.xy;
return Out;
}
f2fb PS(v2f IN,
uniform sampler2D DiffuseMap)
{
f2fb OUT;
//fetch base color
float4 color = tex2D(DiffuseMap,IN.TexCoord0 );
//fetch vertex color
float4 vertexColor=IN.color;
OUT.col = color *vertexColor;
return OUT;
}
sampler2D diffuseSampler = sampler_state
{
Texture = <diffuseTexture>;
MinFilter = Linear;
MagFilter = Linear;
MipFilter = Linear;
ADDRESSU = WRAP;
ADDRESSV = WRAP;
};
technique tech
{
pass P0
{
ZEnable = true;
ZWriteEnable = false;
AlphaBlendEnable = TRUE;
SrcBlend = SRCALPHA;
DestBlend = ONE;//InvSrcAlpha;
CullMode = None;
ShadeMode = Gouraud;
// shaders
VertexShader = compile vs_2_0 VS();
PixelShader = compile ps_2_0 PS(diffuseSampler);
}
}
technique tech_cullModeCW
{
pass P0
{
ZEnable = true;
ZWriteEnable = false;
AlphaBlendEnable = TRUE;
SrcBlend = SRCALPHA;
DestBlend = ONE;//InvSrcAlpha;
CullMode = CW;
ShadeMode = Gouraud;
// shaders
VertexShader = compile vs_2_0 VS();
PixelShader = compile ps_2_0 PS(diffuseSampler);
}
}
----
补充：
1，内置的dx shader vertexcolor.fx在3dmax2012中会报错，在3dmax2010中vertexcolor.fx中是可用的。
2，仿照vertexcolor.fx，顶点色col用mapchannel 0，顶点透明度alpha用mapchannel -2。那个diffuse纹理，用一个跟它们不冲突的通道即可，我这里用的是mapchannel 1。
补充2:
3dmax里似乎没有办法控制渲染顺序，所以在复杂场景中，使用了blend的物体，显示结果并不一定符合预期。