Assignment 3 Discussion

You have to change 2 things in the Makefile. Here is one where you only change one thing:

PBRT_DIR = ../src-1.02
PBRT_BIN_DIR = $(PBRT_DIR)/bin


ARCH = $(shell uname)


ifneq ($(ARCH),Darwin)
DLLLIB = -ldl
endif

EXRINCLUDE=../OpenEXR/include
EXRLIBS=-lIlmImf -lImath -lIex -lHalf -lz

CXX=g++
OPT=-O2
INCLUDE=-I. -I$(PBRT_DIR)/core -I$(EXRINCLUDE)
WARN=-Wall
CWD=$(shell pwd)
CXXFLAGS=$(OPT) $(INCLUDE) $(WARN)
LIBS=$(LEXLIB) $(DLLLIB) -L$(EXRLIBDIR) $(EXRLIBS) -lm
ifeq ($(ARCH), Darwin)
  SHARED_LDFLAGS = -flat_namespace -undefined suppress -bundle -noprebind
  LRT_LDFLAGS=$(OPT) -L/sw/lib
  #PBRTPRELINK=-Wl,-all_load
  INCLUDE += -I/sw/include
  CXX=ccache g++
  EXRLIBDIR=../OpenEXR/lib-osx
  WARN += -Wno-long-double
else
  SHARED_LDFLAGS = -shared
  LRT_LDFLAGS=-rdynamic $(OPT)

  EXRLIBDIR=../cs348b_extras/lib

  PBRTPRELINK=-Wl,--export-dynamic -Wl,-whole-archive
  PBRTPOSTLINK=-Wl,-no-whole-archive
endif
LD=$(CXX) $(OPT)

CAMERAS      = realistic

CAMERAS_DSOS      := $(CAMERAS:=.so)

CORE_HEADERFILES = api.h camera.h color.h dynload.h film.h geometry.h \
                  kdtree.h light.h pbrt.h material.h mc.h mipmap.h octree.h \
                  paramset.h primitive.h reflection.h sampling.h scene.h \
                  shape.h texture.h timer.h tonemap.h transform.h transport.h \
                  volume.h

CORE_HEADERS := $(addprefix ../core/, $(CORE_HEADERFILES) )

.SECONDARY: $(CAMERAS_OBJS)

default: $(CAMERAS_DSOS)
        cp $< $(PBRT_BIN_DIR)

$(CORE_LIB): $(CORE_OBJS)
        ar rcs $(CORE_LIB) $(CORE_OBJS)

%.so: %.o
        @$(LD) $(SHARED_LDFLAGS) $^ -o $@

%.o: cameras/%.cpp $(CORE_HEADERS)
        @echo "Building Realistic Camera Plugin \"$*\""
        @$(CXX) $(CXXFLAGS) -o $@ -c $<

clean:
        rm -f *.o *.so

Q.1

Are the hw3_scene.pbrt and hw3_scene2.pbrt supposed to work without changes?

hw3_scene.pbrt
pbrt version 1.020 of Apr  9 2006 at 16:12:53
Copyright (c)1998-2005 Matt Pharr and Greg Humphreys.
For educational use only; commercial use expressly forbidden.
Error: Scene description must be inside world block; "Texture" not allowed. Ignoring.
        Line 8, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Texture" not allowed. Ignoring.
        Line 9, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 10, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 15, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 16, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 21, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Texture" not allowed. Ignoring.
        Line 22, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 23, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 28, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Texture" not allowed. Ignoring.
        Line 29, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 30, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 34, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectBegin" not allowed. Ignoring.
        Line 34, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 36, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 41, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectEnd" not allowed. Ignoring.
        Line 41, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectBegin" not allowed. Ignoring.
        Line 43, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 45, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 50, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectEnd" not allowed. Ignoring.
        Line 50, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectBegin" not allowed. Ignoring.
        Line 53, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 55, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 61, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectEnd" not allowed. Ignoring.
        Line 61, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectBegin" not allowed. Ignoring.
        Line 63, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 65, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 71, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectEnd" not allowed. Ignoring.
        Line 71, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectBegin" not allowed. Ignoring.
        Line 73, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Texture" not allowed. Ignoring.
        Line 75, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 76, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 81, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectEnd" not allowed. Ignoring.
        Line 81, file hw3_scene.pbrt
Error: Scene description must be inside world block; "AttributeBegin" not allowed. Ignoring.
        Line 83, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Material" not allowed. Ignoring.
        Line 85, file hw3_scene.pbrt
Error: Scene description must be inside world block; "Shape" not allowed. Ignoring.
        Line 87, file hw3_scene.pbrt
Error: Scene description must be inside world block; "AttributeEnd" not allowed. Ignoring.
        Line 87, file hw3_scene.pbrt
Error: Scene description must be inside world block; "AttributeBegin" not allowed. Ignoring.
        Line 89, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 92, file hw3_scene.pbrt
Error: Scene description must be inside world block; "AttributeEnd" not allowed. Ignoring.
        Line 93, file hw3_scene.pbrt
Error: Scene description must be inside world block; "AttributeBegin" not allowed. Ignoring.
        Line 95, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 99, file hw3_scene.pbrt
Error: Scene description must be inside world block; "AttributeEnd" not allowed. Ignoring.
        Line 100, file hw3_scene.pbrt
Error: Scene description must be inside world block; "AttributeBegin" not allowed. Ignoring.
        Line 102, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 106, file hw3_scene.pbrt
Error: Scene description must be inside world block; "AttributeEnd" not allowed. Ignoring.
        Line 107, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 110, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 113, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 116, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 119, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 122, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 125, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 128, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 131, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 134, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 137, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 140, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 143, file hw3_scene.pbrt
Error: Scene description must be inside world block; "ObjectInstance" not allowed. Ignoring.
        Line 146, file hw3_scene.pbrt

Q.2

Is the small angle (curvature) approximation sufficient when doing the weight computation? From what I can tell the paper just goes with a planar disc from the start, and only mentions the assumption that the disc is parallel to the film plane.

Q.3

What does the axpos = 0 for the last lens in dgauss.50mm.dat signify? How can the thickness of the lens be zero?

Q.4

Do we calculate the focal length from the parameters in the file or can we assume it to be the values mentioned in the comments in the dat file. For eg 50mm in dgauss lens?

Q.5

Also, what does filmdistance mean? Is it the distance between the film and the focal point or the distance from the film to the first lens?