환경 세팅
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호환성
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Settings
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Render Engine: LuxCoreRender
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Compute Device: CPU
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Light Tracing: On
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Light Rays: 100%
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← 100%로 해야 끝까지 다 추적
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~ Cache: Off
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캐시를 키면 속도는 빨라지는 대신에 블러해짐
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당연히 프리뷰로는 Caustic 제대로 표현 안 함
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Render > Render Image 눌러서 렌더링 돌려야 됨
100.00 What is Caustics?
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describes the patterns of light and color
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that occur when light rays are reflected or refracted from a surface
"Ray tracing"
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really the top-level term to describe the general method, i.e. following the path of a ray of light. Other terms decribe how that is done, for example:
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빛 광선을 따라가는 기법들을 부르는 일반적인 용어. 아래 용어들은 세부 기법.
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"Light tracing"
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starts at a light source and will end at the camera (same as in reality)
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시작: 광원, 끝: 카메라
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물리적 실제와 같음 (”빛”을 따라감)
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"Path tracing"
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inverse, starts at the camera and ends at the light. This works because (geometric) light paths are reversible.
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시작: 카메라, 끝: 광원
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물리적 실제와 거꾸로. 거꾸로 타고 가도 어차피 같을테니까. (”길”을 역추적)
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장점
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카메라에 들어올 광원만 추적하니까 효율적
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단점
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카메라에 들어오지는 않지만 중간에 영향을 주는 광원이 있었다면 결과에 반영이 제대로 안 될 수도 있음
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그러면 결과가 이상하게 나옴
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"Bidirectional"
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starts at both ends and can additionally connect in the middle.
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시작: 카메라 & 광원
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장점
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위 두 기법의 장단점을 적절히 보완
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단점
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Path tracing에 비해 느림
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"Physically-based materials": Here, the software algorithm is taken from some scientific description of a material, i.e. an equation found in a text book.
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"Non-physical" materials may use any made up equations to describe them.
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"Spectral": The most important difference is that in a spectral rendering engine, the light paths can depend on the color of the light. I.e. when a light hits a surface, and a new direction for the next ray is calculated, the color is included in the equation somehow. Additionally, each ray does not carry RGB information but only intensity.
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As opposed to that, in a "non-spectral" engine, the color is not inlcuded in the geometry calculations. Each ray has an RGB color that is modified at each intersection.
Lens Design vs. Rendering
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Scientific/engineering vs. Good looking
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Sequential vs. Non sequential
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Lens design is typically done with "sequential" ray tracing. Imagine a camera lens: The main rays forming the image will go through the lens one surface by one in order. This elimintes the step of finding which surface is hit next, because you already know. (Even for lens flares, you jsut change direction, go back a few, then forward again)
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LuxCore, Cycles etc. are built around being "non.sequential". Rays may bounce from any surface to any other. Software like Zemax can do this too, e.g. to compute stray light from the lens mount, but It's not their main application.
101.01
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위 예시에서는 기본적인 접근 방법 설명
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Light Rays 100%
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비슷한 결과를 더 빠르게 렌더링하기 위한 최적화
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Cache 사용
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위 예시 같은 기본적인 scene에선 Light Rays 100%로 올려도 잘 렌더링되나, Orange example scene만 해도 Light Rays 100% 렌더링 하려면 너무 시간 오래 걸림
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오래 걸린다 정도가 아니라 내 PC에서는 사실상 안 됨
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기본 세팅으로는 halt 조건으로 중간에 잘려버림
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Cache를 켜도 큰 의미는 없음
101.02
101.03 Orange example scene
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Blender 3.6 + BlendLuxCore latest
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X
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Blender 2.93 LTS + BlendLuxCore v2.6
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Blender 3.6 LTS + BlendLuxCore v2.7beta1