Merge pull request #2434 from mvorbrodt/master

Generate attenuation constants if non are provided in the Blender file…

code/BlenderLoader.cpp

@@ -1225,6 +1225,16 @@ aiLight* BlenderImporter::ConvertLight(const Scene& /*in*/, const Object* obj, c
         case Lamp::Type_Local:
             out->mType = aiLightSource_POINT;
             break;
+        case Lamp::Type_Spot:
+            out->mType = aiLightSource_SPOT;
+
+            // blender orients directional lights as facing toward -z
+            out->mDirection = aiVector3D(0.f, 0.f, -1.f);
+            out->mUp = aiVector3D(0.f, 1.f, 0.f);
+
+            out->mAngleInnerCone = lamp->spotsize * (1.0f - lamp->spotblend);
+            out->mAngleOuterCone = lamp->spotsize;
+            break;
         case Lamp::Type_Sun:
             out->mType = aiLightSource_DIRECTIONAL;
 
@@ -1255,6 +1265,23 @@ aiLight* BlenderImporter::ConvertLight(const Scene& /*in*/, const Object* obj, c
     out->mColorAmbient = aiColor3D(lamp->r, lamp->g, lamp->b) * lamp->energy;
     out->mColorSpecular = aiColor3D(lamp->r, lamp->g, lamp->b) * lamp->energy;
     out->mColorDiffuse = aiColor3D(lamp->r, lamp->g, lamp->b) * lamp->energy;
+
+    // If default values are supplied, compute the coefficients from light's max distance
+    // Read this: https://imdoingitwrong.wordpress.com/2011/01/31/light-attenuation/
+    //
+    if (lamp->constant_coefficient == 1.0f && lamp->linear_coefficient == 0.0f && lamp->quadratic_coefficient == 0.0f && lamp->dist > 0.0f)
+    {
+        out->mAttenuationConstant = 1.0f;
+        out->mAttenuationLinear = 2.0f / lamp->dist;
+        out->mAttenuationQuadratic = 1.0f / (lamp->dist * lamp->dist);
+    }
+    else
+    {
+        out->mAttenuationConstant = lamp->constant_coefficient;
+        out->mAttenuationLinear = lamp->linear_coefficient;
+        out->mAttenuationQuadratic = lamp->quadratic_coefficient;
+    }
+
     return out.release();
 }
 

code/BlenderScene.cpp

@@ -211,9 +211,12 @@ template <> void Structure :: Convert<Lamp> (
     ReadField<ErrorPolicy_Warn>(dest.b,"b",db);
     ReadField<ErrorPolicy_Warn>(dest.k,"k",db);
     ReadField<ErrorPolicy_Igno>(dest.energy,"energy",db);
-    ReadField<ErrorPolicy_Igno>(dest.dist,"dist",db);
+    ReadField<ErrorPolicy_Warn>(dest.dist,"dist",db);
     ReadField<ErrorPolicy_Igno>(dest.spotsize,"spotsize",db);
     ReadField<ErrorPolicy_Igno>(dest.spotblend,"spotblend",db);
+    ReadField<ErrorPolicy_Warn>(dest.constant_coefficient, "coeff_const", db);
+    ReadField<ErrorPolicy_Warn>(dest.linear_coefficient, "coeff_lin", db);
+    ReadField<ErrorPolicy_Warn>(dest.quadratic_coefficient, "coeff_quad", db);
     ReadField<ErrorPolicy_Igno>(dest.att1,"att1",db);
     ReadField<ErrorPolicy_Igno>(dest.att2,"att2",db);
     ReadField<ErrorPolicy_Igno>(temp,"falloff_type",db);

code/BlenderScene.h

@@ -538,6 +538,10 @@ struct Lamp : ElemBase {
       float energy, dist, spotsize, spotblend;
       //float haint;
 
+      float constant_coefficient;
+      float linear_coefficient;
+      float quadratic_coefficient;
+
       float att1, att2;
       //struct CurveMapping *curfalloff;
       FalloffType falloff_type;