# Surface Space Ambient Occlusion
# ===============================

# Demonstrate the usage of surface space ambient occlusion.
# Surface space ambient occlusion (SSAO) can approximate shadows more
# efficiently than ray-tracing and produce similar results. Use this when you wish
# to plot the occlusion effect that nearby meshes have on each other by blocking
# nearby light sources.
# See Kitware: Screen-Space Ambient Occlusion for more details
# First, let's create several cubes nearby each other

import pyvista as pv
from pyvista import examples

grid = pv.ImageData(dimensions=(5, 5, 5)).explode(0.2)

# Plot with defaults
# ==================

# Let's plot this without SSAO. Note how the lighting is identical for each
# cube.
pl = pv.Plotter()
pl.add_mesh(grid)
pl.show()

# Plot with SSAO
# ==============

# Now plot this with SSAO using `enable_ssao()`. Note how adjacent
# cubes affect the lighting of each other to make it look less artificial.
# With a low `kernel_size`, the image will be rendered quickly at the expense
# of quality.
pl = pv.Plotter()
pl.add_mesh(grid)
pl.enable_ssao(kernel_size=32)
pl.show()

# Improve the SSAO rendering
# ==========================

# Here we've increased the `kernel_size` to improve the quality of the SSAO
# and also enabled SSAA anti-aliasing to smooth out any of the artifacts
# created from SSAO.
pl = pv.Plotter()
pl.add_mesh(grid)
pl.enable_ssao(kernel_size=128)
pl.enable_anti_aliasing('ssaa')
pl.show()

# Plot a CAD model without SSAO
# =============================

# Here's another example without SSAO. This is a CAD model of a Raspberry PI
# case.
mesh = examples.download_cad_model_case()

pl = pv.Plotter()
pl.add_mesh(mesh, smooth_shading=True, split_sharp_edges=True)
pl.enable_anti_aliasing('ssaa')
pl.camera.zoom(1.7)
pl.show()

# Plot with SSAO
# ==============

# Here's the same CAD model with SSAO. Note how we had to increase both
# `radius` and `bias` due to the relative scene size.
# Note that the occlusion still seems quite small. In the next example we will
# increase the `radius` to increase the effect of the occlusion.
pl = pv.Plotter()
pl.add_mesh(mesh, smooth_shading=True, split_sharp_edges=True)
pl.enable_ssao(radius=2, bias=0.5)
pl.enable_anti_aliasing('ssaa')
pl.camera.zoom(1.7)
pl.show()

# Increase the Radius
# ===================

# Here we've increased the `radius` to the point where the case occlusion now
# seems realistic without it becoming overwhelming.
pl = pv.Plotter()
pl.add_mesh(mesh, smooth_shading=True, split_sharp_edges=True)
pl.enable_ssao(radius=15, bias=0.5)
pl.enable_anti_aliasing('ssaa')
pl.camera.zoom(1.7)
pl.show()

# ----------------------------------------------------------------------
# Generated by sphinx-examples-as-code https://github.com/pyvista/sphinx-examples-as-code