7 research outputs found
Multi-Scale 3D Gaussian Splatting for Anti-Aliased Rendering
3D Gaussians have recently emerged as a highly efficient representation for
3D reconstruction and rendering. Despite its high rendering quality and speed
at high resolutions, they both deteriorate drastically when rendered at lower
resolutions or from far away camera position. During low resolution or far away
rendering, the pixel size of the image can fall below the Nyquist frequency
compared to the screen size of each splatted 3D Gaussian and leads to aliasing
effect. The rendering is also drastically slowed down by the sequential alpha
blending of more splatted Gaussians per pixel. To address these issues, we
propose a multi-scale 3D Gaussian splatting algorithm, which maintains
Gaussians at different scales to represent the same scene. Higher-resolution
images are rendered with more small Gaussians, and lower-resolution images are
rendered with fewer larger Gaussians. With similar training time, our algorithm
can achieve 13\%-66\% PSNR and 160\%-2400\% rendering speed improvement at
4-128 scale rendering on Mip-NeRF360 dataset compared to the
single scale 3D Gaussian splatting
A Bis-benzopyrroloisoquinoline Alkaloid Incorporating a Cyclobutane Core and a Chlorophenanthroindolizidine Alkaloid with Cytotoxic Activity from <i>Ficus fistulosa</i> var. <i>tengerensis</i>
Tengerensine (<b>1</b>), isolated
as a racemate and constituted
from a pair of bis-benzopyrroloisoquinoline enantiomers, and tengechlorenine
(<b>2</b>), purified as a scalemic mixture and constituted from
a pair of chlorinated phenanthroindolizidine enantiomers, were isolated
from the leaves of <i>Ficus fistulosa</i> var. <i>tengerensis</i>, along with three other known alkaloids. The structures of <b>1</b> and <b>2</b> were determined by spectroscopic data
interpretation and X-ray diffraction analysis. The enantiomers of <b>1</b> were separated by chiral-phase HPLC, and the absolute configurations
of (+)-<b>1</b> and (−)-<b>1</b> were established
via experimental and calculated ECD data. Compound <b>1</b> is
notable in being a rare unsymmetrical cyclobutane adduct and is the
first example of a dimeric benzopyrroloisoquinoline alkaloid, while
compound <b>2</b> represents the first naturally occurring halogenated
phenanthroindolizidine alkaloid. Compound (+)-<b>1</b> displayed
a selective in vitro cytotoxic effect against MDA-MB-468 cells (IC<sub>50</sub> 7.4 μM), while compound <b>2</b> showed pronounced
in vitro cytotoxic activity against all three breast cancer cell lines
tested (MDA-MB-468, MDA-MB-231, and MCF7; IC<sub>50</sub> values of
0.038–0.91 μM)