panda3d-simplepbr

A straight-forward, easy-to-use PBR render pipeline for Panda3D. This project aims to be a drop-in replacement for Panda3D's auto-shader. The PBR shader is heavily inspired by the Khronos glTF Sample Viewer. Note: this project does not make an attempt to match a reference renderer.

Features

• Supports running on a wide range of hardware with an easy OpenGL 2.1+ requirement
• Forward rendered metal-rough PBR
• All Panda3D light types (point, directional, spot, and ambient)
• Filmic tonemapping
• Normal maps
• Emission maps
• Occlusion maps
• Basic shadow mapping for DirectionalLight and Spotlight
• Post-tonemapping color transform via a lookup table (LUT) texture
• IBL diffuse and specular

Installation

Use pip to install the panda3d-simplepbr package:

pip install panda3d-simplepbr

To grab the latest development build, use:

pip install git+https://github.com/Moguri/panda3d-simplepbr.git

Usage

Just add simplepbr.init() to your ShowBase instance:

from direct.showbase.ShowBase import ShowBase

import simplepbr

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

        simplepbr.init()

The init() function will choose typical defaults, but the following can be modified via keyword arguments:

render_node : The node to attach the shader too, defaults to base.render if None

window : The window to attach the framebuffer too, defaults to base.win if None

camera_node : The NodePath of the camera to use when rendering the scene, defaults to base.cam if None

msaa_samples : The number of samples to use for multisample anti-aliasing, defaults to 4

max_lights : The maximum number of lights to render, defaults to 8

use_normal_maps : Use normal maps to modify fragment normals, defaults to False (NOTE: Requires models with appropriate tangents defined)

use_emission_maps : Use emission maps, defaults to True

use_occlusion_maps : Use occlusion maps, defaults to False (NOTE: Requires occlusion channel in metal-roughness map)

enable_shadows : Enable shadow map support, defaults to True

shadow_bias : A global bias for shadow mapping (increase to reduce shadow acne, decrease to reduce peter-panning), defaults to 0.005

enable_fog : Enable exponential fog, defaults to False

exposure : a value used to multiply the screen-space color value prior to tonemapping, defaults to 1.0

use_330 : Force shaders to use GLSL version 330 (if True) or 120 (if False) or auto-detect if None, defaults to None

use_hardware_skinning : Force usage of hardware skinning for skeleton animations or auto-detect if None, defaults to None

sdr_lut : Color LUT to use post-tonemapping

sdr_lut_factor : Factor (from 0.0 to 1.0) for how much of the LUT color to mix in, defaults to 1.0

env_map : An EnvMap or cubemap texture path to use for IBL, defaults to None

calculate_normalmap_blue : Calculate the blue channel (Z-axis) for a normal map in the shader (allows saving memory/bandwidth by using 2 channel normal maps), defaults to True

Those parameters can also be modified later on by setting the related attribute of the simplepbr Pipeline returned by the init() function:

        pipeline = simplepbr.init()
        
        ...
        
        pipeline.use_normals_map = True

Textures

simplepbr expects the following textures are assigned to the following texture stages:

• BaseColor - Modulate
• MetalRoughness - Selector
• Normals - Normal
• Emission - Emission

Example

For an example application using panda3d-simplepbr check out the viewer in the panda3d-gltf repo.

Running Tests

First install panda3d-simplepbr in editable mode along with test extras:

pip install -e .[test]

Then run the test suite with pytest:

pytest

Building Wheels

Install build:

pip install --upgrade build

and run:

python -m build

License

B3D 3-Clause