forge-gobo-spotlight

To project a gobo texture in SDL GPU, you compute a light view-projection matrix to drive texture projection, cone masking, and shadow mapping onto scene geometry. You need to load a gobo texture as UNORM and configure proper samplers for the spotlight.

Casting shadows from a projected spotlight in SDL requires a 2D shadow depth map using D32_FLOAT format. You render the scene depth from the light's perspective into this map, then sample it to occlude light and create depth-based shadows aligned with the gobo projection.

Yes, SDL GPU supports inner and outer cone angles for precise spotlight focus. By applying cone falloff calculations in your shaders, you can create cinematic or stage-style lighting effects that blend smoothly between the inner and outer cone boundaries.

A single light view-projection matrix handles shadow mapping, gobo projection, and cone masking by transforming vertex positions into the spotlight's clip space. This unified matrix ensures the projected texture, shadow depth lookup, and cone boundary falloff all align accurately.

You need a D32_FLOAT 2D texture for the shadow depth map and a UNORM texture for the gobo pattern. These formats ensure accurate depth precision for shadow occlusion and correct color projection for the spotlight pattern on geometry.