project titan - study.houdini

PROJECT TITAN https://www.sidefx.com/titan/
- 배경
PROJECT PEGASUS https://www.sidefx.com/pegasus/
- 지형

PROJECT TITAN STACKING TOOL

https://www.sidefx.com/tutorials/project-titan-stacking-tool/
- by Thomas Tobin - https://www.artstation.com/thomasctobin
- https://www.youtube.com/playlist?list=PLXNFA1EysfYm0MPSArwg-Kdnb1fWyat1K
시뮬해서 떨어지게 하는 부분이 잼씀.
어럽네 중간에 디프리케이트된 노드랑 조금 개념에 안맞는게 있음.
pivot문제랑 py_max구하는 부분

Groupd_props => gr_base_layer

1 | Unreal Engine Setup

속성
- AssetPath
- Width
- Height
- Length
- Rotation
- Scale_MIN
- Scale_MAX
Create > Place Actors > Panel
- Geometry > Box
  - Activate Brush Editing Editing Mode (Shift + 6)
Houdini
- Windows > Houdini Engine Session Sync

2 | Setting up the HDA

Object Merge로 언리얼 DataTable을 가져오면 point에 attribute를 가지게 됨.
https://www.sidefx.com/ja/forum/topic/86532/?page=1#post-374007
- Labs Building From Patterns 편집

정보를 불러와서 더미에 셋팅

CSV Import 노드 (csv를 로드)
- Fill Attribute Info from Header로 간편하게 로드하자
필요시 Attribute Rename을 사용하여 이름을 바꾸자

Wrangle (Point)

  vector s = set(
      @Width,
      @Height,
      @Length
  );
  @scale = s;
  @P = {0, 0, 0};

Color
- Color Type: Random from Attribute
- Attribute : AssetPath
Copy to Point - 박스랑
- Pack and Instance
Connectivity - Primitive 로 class 어트리뷰트로 각 박스별 그룹지어주고
Attribute Promote - 최대값을 저장해둔다
- Original Name : class
- Original Class : Primitive
- New Class : Detail
- Promotion Method : Maximum
- Change New Name : max
- Delete Original : 언체크
Unpack
- Transfer Attribute : *

primitive:
    +class

detail:
    +max

더미 위치 조정

class(primitive)를 point(variant)로 변환

Foreach Primitive - Piece Attribute : class
- Match Size
  - Justify Y : Min
- Bound
- Attribute Transfer
  - Detail
Attribute Promote
- Original Name : class (primitive)
- New Name : variant (point)
Null: INPUT_SCATTER

point:
    +variant

primitive:
    -class =>  point:variant

detail:
    max

3 | Packing Assets

배치 구역 밑바닥

Object Merge로 영역을 가져고
Group
- Keep by Normal
  - Direction: 0, -1, 0
  - Spread Angle : 20
Blast
Reverse
Null : OUT_BOTTOM_LAYER

배치 구역 설정

OUT_BOTTOM_LAYER에 점을 뿌리고 variant를 랜덤화시킨다.

Scatter and Algin 으로 점을 뿌리고
- https://www.sidefx.com/docs/houdini/nodes/sop/scatteralign.html
- Point Count Method : By Density
- Density Scale에 따라 오브젝트 크기도 달라짐
Wrangle (Point)
- @id = @ptnum;
Attribute Randomize
- Attribute Name : variant
- Dimensions: 1
- Distribution : Uniform(Discrete)
- Max Value : detail("-1", "max", 0)
- Spare Input : ../INPUT_SCATTER
Attribute Cast
- Attributes : variant
- Precision: 16-bit integer
Null: INPUT_SPREAD_POINTS

+point:id==@ptnum
+point:orient
+point:variant        // random from ../INPUT_SCATTER's detail:max

iscale셋팅

Copy to Point - INPUT_SPREAD_POINTS의 variant 기반으로 INPUT_SCATTER를 변형하며 뿌리기
- Piace Attribute : variant
- Pack and Instance
Attribute Transfer
- Detail도 활성화
Attribute Randomize
- Attribute Name : iscale
- Attribute Class : Primitive
- Distribution : Uniform(Discrete)
- Dimensions : 1
- Min Value:
- Max Value:
- Step Size:
Unpack
- Transfer Attribute : *
Null : RANDOMIZE_ISCALE

point:
    variant
    id

primitive:
    +iscale

detail:max

uv layout을 사용한 배치

UV Layout
- UV Attribute : P / ZX Projection
- Island Scale Attribute: iscale
- Axis Alignment : None
- Packing
  - Scale: Fixed
  - Spread Islands in Cavities of Other Islands
- Targets
  - Pack Into : Islands From Second Input
    - 두번째 입력으로 Object Merge: ../OUT_BOTTOM_LAYER > Remesh TODO
  - UV Attribute : P / ZX Projection
- Nonpacked Polygons : nonpacked
Blast : nonpacked
Null : OUT_BOTTOM_LAYER_PACKED

point:
    variant
    id

primitive:
    iscale
    +group:nonpack

detail:
    max
    +coverage
    +numnopacked

4 | Stacking Assets

50분 정도 내용이라 따라가기 힘듬

Partion 노드는 deprecated.
- Use the Groups from Name node instead.
Attribute Promote
- id(point) => id(Primitive)

Pack

https://www.sidefx.com/docs/houdini/nodes/sop/pack.html

- Path Attribute: op:\`opfullpath('.')\`
- Name Attribute: id
- Create Packed Fragments: 체크 해제
- Transfer Attributes: *

Group : gr_base_layer

point:
    variant
    -id =>  primitive:id

primitive:
    +id
    +path  ex) op:/obj/geo1/pack1/0
    iscale
    -group:nonpack

detail:
    -max
    -coverage
    -numnopacked

피드백을 이용해서 한단씩 쌓기

For-Loop with Feedback
- Null: PROCESS
- Null: FEEDBACK 은 나중에 머지용으로 빼두고

PROCESS 에서 상단면을 구하고

Unpack
Group (gr_top_mesh)
- Keep by Normal
  - Direction: 0, 1, 0
  - Spread Angle : 20
Blast (gr_top_mesh)
Group Promotion (gr_top_mesh)
- Primitive to Point

상단면에서 가장 높은 면만을 고른 뒤

Wrangle (Primitive)
- f@py = @P.y;
Attribute Promote
- py(primitive) => py_max(detail)
- Promotion Method : Maximum
blast
```
@py=`detail(0, "py_max", 0)`
```

무리지어 묶는다

Pack (pack_for_cluster)
Cluster Points
- https://www.sidefx.com/docs/houdini/nodes/sop/clusterpoints.html
  - Point attribute가 cluster가 생기고 해당 클러스터 번호가 들어간다.
- Clusters: ch("spare_input0") * 1.5
  - Clust : (모여있는 )무리
  - Clusters 수치를 조절하여 뭉처있는 것들을 조절
- Spare Input 0 : `npoints(-2)`
  - The first spare input is -1, the second is -2, and so on
- Spare Input 1 : ../pack_for_cluster
Attribute Promote
- cluster:point > primitive
Unpack
- Transfer Attribute : *

무리를 감싸는 영역을 만들고

foreach primitive로 Cluster 구역별로 묶기
- Piece Attribute : cluster
Shrinkwrap (2D) 로 엮여있는것들을 묶어주고
Transform 조금작게 해주자
- Uniform Scale: 0.8
- Pivot Translate: $CEX/$CEY/$CEZ
Remesh
Null: HIGHER_AREA

해당 영역에 다시 적층하자

RANDOMIZE_ISCALE를 object merge로 가져오고, 다시 attribute randomize를 시켜주자. 그리고

UV Layout
- UV Attribute : P / ZX Projection
- Island Scale Attribute: iscale
- Axis Alignment : None
- Packing
  - Scale: Fixed
  - Spread Islands in Cavities of Other Islands
- Targets
  - Pack Into : Islands From Second Input
    - 두번째 입력으로 Object Merge: ../OUT_BOTTOM_LAYER > Remesh TODO
  - UV Attribute : P / ZX Projection
- Nonpacked Polygons : nonpacked
Blast : nonpacked
Attribute Promote
- id:point > primitive
Pack
그다음 FEEDBACK과 머지
Attribute Promote
- iscale:primitive => pscale:point
Copy To Point - OUT_HIGH과
- Piace Attribute : variant
- Pack and Instance
- 추가 Points by Copying : pscale orient

5 | Simulation

Group (gr_active)
- Point
- BaseGroup: gr_base_layer
Split: gr_activate
- unpack > Null (ACTIVE)
- unpack > Null (NON_ACTIVE)
NON_ACTIVE에서
Wrangle (point)
- f@active = 1;
- v@v = chv("direction") * chf("boost") * rand(@ptnum);
RBD Bullet Solver
- Output: Transfer Attribute : orient
- OUT_OBJECT_PLACEMENT랑 grid랑 MatchSize하고 ACTIVE랑 머지한걸 input4에 넣음
Timeshift
- Frame: 50
Group : gr_inside_bound
- Keep in Bouding Region
  - Bouding Object(point or vertices only)로 감싸는 영역만 하고
Blast : gr_inside_bound
- Delete Non Selected
그리고 ACTIVE랑 머지

이제 포인트만 남기도록

Clean
- Remove Attribs: * ^N ^up ^orient ^scale ^pscale ^unreal_instance ^unity_instance
Connectivity
- Primitive
Foreach Primitive - Piece Attribute: class
gr_piece
Wrangle (detail)
- vector min;
- vector max;
- getbbox(min, max);
- vector center = (min + max) / 2;
- vector combo = set(center.x, min.y, center.z);
- addpoint(-1, combo);
Blast : gr_piece
Attribute Transfer 전부

그러면 이제 끝

PROJECT TITAN CABLE TOOL

https://www.sidefx.com/tutorials/project-titan-cable-tool/
- https://www.youtube.com/playlist?list=PLXNFA1EysfYnkP5GncdwIVsZABbZ2z_Ud
라인 활용 Vellum Hair를 이용한 시뮬레이션
Connect Adjacent Pieces 인접 조각 연결로 서브 케이블 만듬

2 | Create the Main Cables

Circle
Mountain
- Noise Along Vector 해제 및 XY만 활성화
Connect Adjacent Pieces - 이렇게 하면 primitive갯수가 늘어나버림
- Adjacent Points
- Search Radious: 10
Convert Line
Attribute Promote
- restlength:primitive => minimum => point:pscale
Attribute Transfer
- 앞서 mountain된것에 point:pscale만 넘겨준다
Sweep
- Line / Resample 한것을 첫번째 인풋으로
- Surface Type: Columns
Attribute Randomize
- random:primitive
Attribute Promote
- random:primitive => random:point
Group by Range (gr_line_pins)
- Point
- Invert Range
- Conectivity/Affect Disconnected Geometry Seperately
Vellum Hair
- Constraint Type: String
- Pin to Animation
  - Pin Points: gr_line_pins
Vellum Solver

3 | Create the Small Cables

4 | Build the Digital Asset

입력을 2개 추가한다
- 1번째 입력은 line을 대체
- 2번째 입력은 컬리전으로 Vellum Hair의 3번째 인자로 들어가게 된다.

5 | Open in Unreal

Attribute Create
- unreal_material

6 | Use Trimsheet Textures

Sweap에서 Compute UVs

UV를 수평으로

Labs Trim Texture Utility
- Initialization Mode: Generate from ID Map 으로 색으로 구분된 ID맵을 입력받아 trim을 생성

없으면 Grid를 활용

Grid
- Row는 ID갯수 +1만큼
Top뷰(2번키)로, Select(s키) 포인트(2번키)로 선택후 Translate(t키)를 눌러 y축 조정
UV Project
- Rotate: 90 / -180 / 0
Primitive Split 으로 각 부분을 나눠주고
Trim Texture Utility
- Initialzie누르면 됨.
Labs Automatic Trim Texture
- UV 크기 비율에 맞추어 알아서 레이아웃시켜줌

PROJECT TITAN IVY TOOL

ivy: 담쟁이덩굴

shrub 관목 (=bush)

PROJECT TITAN PLATFORM TOOL PROJECT TITAN FENCE TOOL PROJECT TITAN TREE PIVOT PAINTER PROJECT TITAN RAILS TOOL PROJECT TITAN VAT CHARACTERS PROJECT TITAN BUILDING TOOL PROJECT TITAN GPT SIGNAGE