Spot light shows no shadow on invisible plane. · google/filament#6178

(6 留言) (1 反應) (1 負責人)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);
    }
}

貢獻者指南

技術棧: cpp
領域: api
議題類型: bug
難度: 4
預計時間: 3-5 days
活動狀態: blocked
清晰度: clear
前置要求: C++shadow mappingFilament APIshader programming
新手友善度: 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.