def size_inside_square_for_texture(texture: core.Texture, square_size: float):
width = texture.get_x_size()
height = texture.get_y_size()
if width < 1 or height < 1:
return None
if width > height:
frame_height = (height / width) * square_size
frame_width = square_size
else:
frame_height = square_size
frame_width = (width / height) * square_size
return core.Vec2(frame_width, frame_height)
def setup_terrain(self):
"""
Terrain info
Units are meters, which is preferable when working with Bullet.
"""
self.terrain_scale = LVector3(512, 512, 100)
self.terrain_pos = LVector3(-256, -256, -70)
# sample values for a 4096 x 4096px heightmap.
#self.terrain_scale = LVector3(4096, 4096, 1000)
#self.terrain_pos = LVector3(-2048, -2048, -70)
"""
Diamond_subdivision is an alternating triangulation scheme and may
produce better results.
"""
use_diamond_subdivision = True
"""
Construct the terrain
Without scaling, any ShaderTerrainMesh is 1x1x1 units.
"""
self.terrain_node = ShaderTerrainMesh()
"""
Set a heightfield, the heightfield should be a 16-bit png and
have a quadratic size of a power of two.
"""
heightfield = Texture()
heightfield.read(self.heightfield_fn)
heightfield.set_keep_ram_image(True)
self.terrain_node.heightfield = heightfield
# Display characteristic values of the heightfield texture
#minpoint, maxpoint, avg = LPoint3(), LPoint3(), LPoint3()
#heightfield.calc_min_max(minpoint, maxpoint)
#heightfield.calc_average_point(avg, 0.5, 0.5, 0.5)
#print("avg: {} min: {} max: {}".format(avg.x, minpoint.x, maxpoint.x))
"""
Set the target triangle width. For a value of 10.0 for example,
the ShaderTerrainMesh will attempt to make every triangle 10 pixels
wide on screen.
"""
self.terrain_node.target_triangle_width = 10.0
if use_diamond_subdivision:
"""
This has to be specified before calling .generate()
The default is false.
"""
load_prc_file_data("", "stm-use-hexagonal-layout true")
self.terrain_node.generate()
"""
Attach the terrain to the main scene and set its scale. With no scale
set, the terrain ranges from (0, 0, 0) to (1, 1, 1)
"""
self.terrain = self.render.attach_new_node(self.terrain_node)
self.terrain.set_scale(self.terrain_scale)
self.terrain.set_pos(self.terrain_pos)
"""
Set a vertex and a fragment shader on the terrain. The
ShaderTerrainMesh only works with an applied shader.
"""
terrain_shader = Shader.load(Shader.SL_GLSL,
"samples/shader-terrain/terrain.vert.glsl",
"samples/shader-terrain/terrain.frag.glsl")
self.terrain.set_shader(terrain_shader)
self.terrain.set_shader_input("camera", base.camera)
# Set some texture on the terrain
grass_tex = self.loader.load_texture(
"samples/shader-terrain/textures/grass.png")
grass_tex.set_minfilter(SamplerState.FT_linear_mipmap_linear)
grass_tex.set_anisotropic_degree(16)
self.terrain.set_texture(grass_tex)
"""
Set up the DynamicHeightfield (it's a type of PfmFile). We load the
same heightfield image as with ShaderTerrainMesh.
"""
self.DHF = DynamicHeightfield()
self.DHF.read(self.heightfield_fn)
"""
Set up empty PfmFiles to prepare stuff in that is going to
dynamically modify our terrain.
"""
self.StagingPFM = PfmFile()
self.RotorPFM = PfmFile()
"""
Set up the BulletHeightfieldShape (=collision terrain) and give it
some sensible physical properties.
"""
self.HFS = BulletHeightfieldShape(self.DHF, self.terrain_scale.z,
STM=True)
if use_diamond_subdivision:
self.HFS.set_use_diamond_subdivision(True)
HFS_rigidbody = BulletRigidBodyNode("BulletTerrain")
HFS_rigidbody.set_static(True)
friction = 2.0
HFS_rigidbody.set_anisotropic_friction(
LVector3(friction, friction, friction/1.3))
HFS_rigidbody.set_restitution(0.3)
HFS_rigidbody.add_shape(self.HFS)
self.world.attach(HFS_rigidbody)
HFS_NP = NodePath(HFS_rigidbody)
HFS_NP.reparent_to(self.worldNP)
"""
This aligns the Bullet terrain with the ShaderTerrainMesh rendered
terrain. It will be exact as long as the terrain vertex shader from
the STM sample is used and no additional tessellation shader.
For Bullet (as for other physics engines) the origin of objects is at
the center.
"""
HFS_NP.set_pos(self.terrain_pos + self.terrain_scale/2)
HFS_NP.set_sx(self.terrain_scale.x / heightfield.get_x_size())
HFS_NP.set_sy(self.terrain_scale.y / heightfield.get_y_size())
# Disables Bullet debug rendering for the terrain, because it is slow.
#HFS_NP.node().set_debug_enabled(False)
"""
Finally, link the ShaderTerrainMesh and the BulletHeightfieldShape to
the DynamicHeightfield. From now on changes to the DynamicHeightfield
will propagate to the (visible) ShaderTerrainMesh and the (collidable)
BulletHeightfieldShape.
"""
self.HFS.set_dynamic_heightfield(self.DHF)
self.terrain_node.set_dynamic_heightfield(self.DHF)
