google/filament

Spot light shows no shadow on invisible plane.

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#6,178 创建于 2022年10月12日

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 (6 评论) (1 反应) (1 负责人)C++ (20,060 star) (2,178 fork)batch import
good first issue

描述

I'm trying to use spot light to cast shadow on invisible plane but can't make it work. I found that directional light can cast shadow on both visible and invisible plane while spot light only shows shadow on visible plane.

directional light + lit plane Screenshot_20221012_171950_com example filamentcamera

directional light + unlit & shaderMultiplier plane Screenshot_20221012_172227_com example filamentcamera

spot light + lit plane Screenshot_20221012_175009_com example filamentcamera

spot light + unlit & shaderMultiplier plane Screenshot_20221012_174330_com example filamentcamera

material of invisible plane

material {
    name : shadow,
    shadingModel : unlit,
    shadowMultiplier : true,
    blending : transparent,
    transparency : twoPassesOneSide,
}
fragment {
    void material(inout MaterialInputs material) {
        prepareMaterial(material);
        material.baseColor = vec4(0.0, 0.0, 0.0, 0.5);
    }
}

贡献者指南

技术栈
cpp
领域
api
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
4
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
3-5 days
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
blocked
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
C++shadow mappingFilament APIshader programming
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
35
研究方向
Investigate Filament's shadow rendering pipeline for spot lights. Compare the spot light shadow map implementation in `src/components/LightManager.cpp` with that of directional lights. Examine how invisible planes with `shadowMultiplier` and `unlit` shading model are handled in the shadow pass. Check if the issue lies in the spot light's shadow map frustum or the shader code that applies shadows to unlit surfaces. Look at recent commits or discussions in the issue for any hints, and consider testing with a minimal reproduction.
Spot light shows no shadow on invisible plane. · google/filament#6178 | Good First Issue