NVPR Tiger 3D Sample

Category: Visuals

Min PC GPU: Fermi-based (GTX 4xx)

Min Tegra Device: Tegra K1

Description

This sample shows how NV_path_rendering content and conventional 3D graphics can be mixed in the same 3D scene.

APIs Used

NV_path_rendering
EXT_direct_state_access

Shared User Interface

The OpenGL samples all share a common app framework and certain user interface elements, centered around the "Tweakbar" panel on the left side of the screen, which lets you interactively control certain variables in each sample.

To show and hide the Tweakbar, simply click or touch the triangular button positioned in the top-left of the view.

Other controls are listed below.

Device	Input	Result
touch	2-Finger Drag	Translate the view
	2-Finger Pinch	Scale the view
mouse	Left-Click Drag	Translate the view
	Right-Click Drag	Scale the view (up:out, down:in)
keyboard	Escape	Quit the application
	Tab	Toggle Tweakbar visibility
gamepad	Start	Toggle Tweakbar visibility

App-Specific Controls

This sample has the following app-specific controls:

keyboard	space	Toggle Animation
	T	Toggle Text
	F	Toggle Path Fill
	S	Toggle Path Stroke
gamepad	Y	Toggle Animation
	X	Toggle Text
	Left Shoulder Button	Toggle Path Fill
	Right Shoulder Button	Toggle Path Stroke

Technical Details

glPathStencilDepthOffsetNVis used to displace depth values forward during the stencil step for the tiger paths so they can be depth tested during the glStencilFillPathNVand glStencilStrokePathNVsteps. Then during the respective cover operations performed by either glCoverStrokePathNVor glCoverFillPathNV, the depth value is always written. This allows the tiger paths to be "stacked up" upon each other in a plane of space without Z fighting artifacts. See "Mixing Path Rendering and 3D" for a more complete explanation.