Scissor Rect Mgun Scissor Optimizations Most important fillrate

Scissor Rect Mgun.

Scissor Optimizations -> Most important fill-rate optimization for stencil shadows -> Hardware does not generate fragments outside the scissor rectangle — very fast -> Scissor rectangle can be applied on a per-light basis or even a per- geometry basis -> Requires that lights have a finite volume of influence

Light Scissor No Light Scissor Shadow volumes extend to edges of viewport Light Scissor Shadow volume fill reduced significantly

Light Scissor -> Project light volume onto the image plane – 조명구가 시야에 보이는 경우, 뷰포트에서 그 광원이 영향을 미치는 영역이 뷰포트 전체가 아닐 수도 있다. 조명구를 이미지 평면에 투영해 그 영역에서만 랜더링. View Frustum Image Plane http: //www. gamasutra. com/view/feature/2942/th e_mechanics_of_robust_stencil_. php? page=2 Camera Light

Calculation Scissor Rect Calculation X축 (Y축도 계산방식이 동일) float f. D = (r 2 * L 2. x - (L 2. x + L 2. z) * (r 2 - L 2. z)); if(f. D <= 0. 0 f) return false; float f. Sqrt. D = sqrtf(f. D); T 0. x = (f. Radius * v. L. x + f. Sqrt. D) / (L 2. x +L 2. z); T 0. z = (f. Radius - T 0. x * v. L. x) / v. L. z; T 1. x = (f. Radius * v. L. x - f. Sqrt. D) / (L 2. x +L 2. z); T 1. z = (f. Radius - T 1. x * v. L. x) / v. L. z; v. P[0] = v. L - f. Radius * T 0; v. P[1] = v. L - f. Radius * T 1;