Screen Aligned Quad vs. Triangle(s)

Screen Aligned Quad vs. Triangle(s)

For rendering screen-filling geometry we usually have to choose between a screen-aligned quad and a screen-aligned triangle. But - is there a difference? If so, which approach is better than the other? This demo shows you the differences between both approaches as well as an Nvidia extension. Refer to CG Internals Blog for theoretical analysis and evaluation together with multiple performance measures. Check out the YouTube video.

Key Binding

[F5] reload shaders
[r] reset record and record anew

[m] switch over to next draw mode
[1] ... draw mode (1) - quad (triangle strip)
[2] ... draw mode (2) - triangle
[3] ... draw mode (3) - fill rectangle extension
[4] ... draw mode (4) - quad (two triangles, two draw calls)
[5] ... draw mode (5) - triangle (attributed vertex cloud, AVC)

[P] measure performance (may take a few minutes)

[T] increment replay speed (by magnitude)
[t] decrement replay speed (by magnitude)

Your graphics card does not support the NV_fill_rectangle extension.
Draw mode 3 will not work properly.

draw mode (1) - quad (triangle strip)