Using simplepbr and an orthographic lens causes a problem with the material.

[serkkz]

When I use an orthographic the lens, the properties of the material are lost, as you can see, the specular glare has disappeared.

from direct.showbase.ShowBase import ShowBase
from panda3d.core import DirectionalLight, Material, NodePath, Camera, OrthographicLens

import simplepbr

class MyApp(ShowBase):
    def __init__(self):
        super().__init__()
        
        # Setting up a new node for rendering.
        my_aspect2d = NodePath("my_aspect2d")

        my_lens = OrthographicLens()
        my_lens.set_film_size(8, 8)
        my_lens.set_near_far(-1000, 1000)

        camera = Camera("camera_orthographic")
        camera.set_lens(my_lens)

        camera_np = NodePath(camera)
        camera_np.set_scale(base.win.get_x_size()/base.win.get_y_size()*1.0, 1.0, 1.0)
        camera_np.reparent_to(my_aspect2d)

        display_region = base.cam.node().get_display_region(0)
        display_region.camera = camera_np
        
        # PBR initialization
        pbr = simplepbr.init(render_node = my_aspect2d, camera_node = camera_np)
        pbr.enable_shadows = True

        # Creating a scene.
        material = Material("test")
        material.set_shininess(128)

        plane = base.loader.load_model("plane.egg")
        plane.set_material(material)
        plane.reparent_to(my_aspect2d)

        sphere = base.loader.load_model("sphere.egg")
        sphere.set_material(material)
        sphere.reparent_to(my_aspect2d)

        light = DirectionalLight("sun")
        light.set_shadow_caster(True, 512, 512)
        light_np = NodePath(light)
        light_np.set_hpr(35, -25, 0)
        light_np.reparent_to(my_aspect2d)

        my_aspect2d.set_light(light_np)

        # Calculation of the bounding box for the shadow map.
        bmin, bmax = my_aspect2d.get_tight_bounds(light_np)
        light_lens = light.get_lens()
        light_lens.set_film_offset((bmin.xz + bmax.xz) * 0.5)
        light_lens.set_film_size(bmax.xz - bmin.xz)
        light_lens.set_near_far(bmin.y, bmax.y)

app = MyApp()
app.run()

The test scene with the perspective lens works as expected.

from direct.showbase.ShowBase import ShowBase
from panda3d.core import DirectionalLight, Material, NodePath

import simplepbr

class MyApp(ShowBase):
    def __init__(self):
        super().__init__()

        # PBR initialization
        pbr = simplepbr.init()
        pbr.enable_shadows = True

        # Creating a scene.
        material = Material("test")
        material.set_shininess(128)

        plane = base.loader.load_model("plane.egg")
        plane.set_material(material)
        plane.reparent_to(render)

        sphere = base.loader.load_model("sphere.egg")
        sphere.set_material(material)
        sphere.reparent_to(render)

        light = DirectionalLight("sun")
        light.set_shadow_caster(True, 512, 512)
        light_np = NodePath(light)
        light_np.set_hpr(35, -25, 0)
        light_np.reparent_to(render)

        render.set_light(light_np)

        # Calculation of the bounding box for the shadow map.
        bmin, bmax = render.get_tight_bounds(light_np)
        light_lens = light.get_lens()
        light_lens.set_film_offset((bmin.xz + bmax.xz) * 0.5)
        light_lens.set_film_size(bmax.xz - bmin.xz)
        light_lens.set_near_far(bmin.y, bmax.y)

app = MyApp()
app.run()

[Moguri]

simplepbr needs to use a different view vector when used with an orthographic camera. It would be nice to do this based on a pre-processor define. We could check projection type of the camera when setting up the shader, but then we would not be able to detect if the projection changed later. This might be "good enough" since the alternatives (checking in the shader, checking every frame via a task) would all add more runtime cost for a pretty uncommon use case.