【Houdini20.5】観覧車をプロシージャルに作ってみる【SOP・VEX】

// ワイヤの種類
int WIRE_TYPE_STANDARD = 0;
int WIRE_TYPE_MERGE_OUTSIDE = 1;
int WIRE_TYPE_MERGE_INSIDE = 2;
int wireType = chi("../wire_type");

// ワイヤの生成数
int wireGenerateCount = chi("../wire_count");

// 内側、外側の円の頂点数を取得
int insideCiclePointCount = npoints(1);
int outsideCiclePointCount = npoints(2);

// ワイヤ生成数に対する頂点ステップ数
int insideCircleStepPoint = int(insideCiclePointCount / wireGenerateCount);
int outsideCircleStepPoint = int(outsideCiclePointCount / wireGenerateCount);

// 外側の円のPoint開始数
int outsideCircleStartPoint = insideCiclePointCount;

// 頂点を結んでワイヤ用のEdgeを作成
for (int i = 0; i < wireGenerateCount; i++) {
    int insideEdgePoint = insideCircleStepPoint * i;
    int outsideEdgePoint = outsideCircleStepPoint * i + outsideCircleStartPoint;
    
    // 基本となるワイヤを生成する
    int wireEdge = addprim(geoself(), "polyline", insideEdgePoint, outsideEdgePoint);
    addvertex(geoself(), wireEdge, insideEdgePoint);
    addvertex(geoself(), wireEdge, outsideEdgePoint);
    setprimattrib(geoself(), "wireedge", wireEdge, 1.0, "set");
    
    // ワイヤの種類によって生成方法を変更する
    if (wireType == WIRE_TYPE_MERGE_INSIDE) {
        // 内側のワイヤをマージ
        int halfInsideCircleStepPoint = int(insideCircleStepPoint / 2);
        int insideEdgePoint1 = insideEdgePoint + halfInsideCircleStepPoint;
        int insideEdgePoint2 = insideEdgePoint - halfInsideCircleStepPoint;
        if (insideEdgePoint2 < 0) {
            insideEdgePoint2 = insideEdgePoint2 + insideCiclePointCount;
        }
        int wireEdge1 = addprim(geoself(), "polyline", insideEdgePoint1, outsideEdgePoint);
        addvertex(geoself(), wireEdge1, insideEdgePoint1);
        addvertex(geoself(), wireEdge1, outsideEdgePoint);
        setprimattrib(geoself(), "wireedge", wireEdge1, 1.0, "set");
        int wireEdge2 = addprim(geoself(), "polyline", insideEdgePoint2, outsideEdgePoint);
        addvertex(geoself(), wireEdge2, insideEdgePoint2);
        addvertex(geoself(), wireEdge2, outsideEdgePoint);
        setprimattrib(geoself(), "wireedge", wireEdge2, 1.0, "set");
        
    } else if (wireType == WIRE_TYPE_MERGE_OUTSIDE) {
        // 外側のワイヤをマージ
        int halfOutsideCircleStepPoint = int(outsideCircleStepPoint / 2);
        int outsideEdgePoint1 = outsideEdgePoint + halfOutsideCircleStepPoint;
        int outsideEdgePoint2 = outsideEdgePoint - halfOutsideCircleStepPoint;
        if (outsideEdgePoint2 < outsideCircleStartPoint) {
            outsideEdgePoint2 = outsideEdgePoint2 + outsideCiclePointCount;
        }
        int wireEdge1 = addprim(geoself(), "polyline", insideEdgePoint, outsideEdgePoint1);
        addvertex(geoself(), wireEdge1, insideEdgePoint);
        addvertex(geoself(), wireEdge1, outsideEdgePoint1);
        setprimattrib(geoself(), "wireedge", wireEdge1, 1.0, "set");
        int wireEdge2 = addprim(geoself(), "polyline", insideEdgePoint, outsideEdgePoint2);
        addvertex(geoself(), wireEdge2, insideEdgePoint);
        addvertex(geoself(), wireEdge2, outsideEdgePoint2);
        setprimattrib(geoself(), "wireedge", wireEdge2, 1.0, "set");
        
    }
}

// ホイールの厚み
float thickness = chf("../circle_thickness");
if (thickness < 0.001)
{
    return;
}

// ホイールの厚みによって動かす量
vector offsetPointPosition = {0, 0, 0};
offsetPointPosition.z = thickness;

int originalNumPoints = npoints(0);
int originalNumPrims = nprimitives(0);

// 押し出してポイントを作成
for (int i = 0; i < originalNumPoints; i++)
{
    vector pointPosition = point(0, "P", i);
    int newPoint = addpoint(0, pointPosition + offsetPointPosition);
    int newWireEdge = addprim(0, "polyline", i, newPoint);
    setprimattrib(geoself(), "wireedge", newWireEdge, 1.0);
    
    // Attributeのコピー
    int prims[] = pointprims(0, i);
    vector colorAttr = prim(0, "Cd", prims[0]);
    setprimattrib(0, "Cd", newWireEdge, colorAttr);
}

// 元のEdge情報から押し出し先のポイントを繋げる
for (int i = 0; i < originalNumPrims; i++)
{
    int points[] = primpoints(0, i);
    int newPoints[];
    foreach (int p; points)
    {
        append(newPoints, p + originalNumPoints);
    }
    int newEdge = addprim(0, "polyline", newPoints);
    
    // Attributeのコピー
    float wireEdgeAttr = prim(0, "wireedge", i);
    setprimattrib(0, "wireedge", newEdge, wireEdgeAttr);
    float circleEdgeAttr = prim(0, "circleedge", i);
    setprimattrib(0, "circleedge", newEdge, circleEdgeAttr);
    vector colorAttr = prim(0, "Cd", i);
    setprimattrib(0, "Cd", newEdge, colorAttr);
}

float lastOutsideRadius = chf("../radius" + itoa((chi("../generate_wheel_list"))));

// 最後の半径の距離に近いポイントにゴンドラ生成ポイントを設定
float distanceCenter = distance({0, 0, 0}, @P);
if (distanceCenter > lastOutsideRadius - 0.01)
{
    setpointattrib(0, "gondlapoint", @ptnum, 1.0);
}