acskyline / vld3d11

d3d11 volumetric light

VLD3D11 (this project is still in progress)

• Tested on: Windows 10, i7-7700K @ 4.20GHz 16.0GB, GTX 1080 15.96GB

• Based on GPU Pro 5: Volumetric Light Effects in Killzone: Shadow Fall and NVDIA Volumetric Lighting Slides

• Cooling fan model from Sketchfab

Current Result

Features

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I. Basic Renderer Functions

overview

details

• Render Texture

• Orbit Camera

• Gizmos

• Texture Mapping

• Basic Geometry

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II. Volumetric Fog

overview

cube	sphere	cone

geometry movement	light movement

details

When rendering the geometry, for each fragment of it, I calculate a ray from the camera to that fragment. Then I use the ray to intersect the geometry in the fragment shader and find the enter and exit position. Then I use ray marching along the vector from enter to exit. During this process, several positions along the ray will be evaluated. For each position, a scalar noise produced by a 3D noise function will be used as a scaling factor which will then be used as a scaling factor to scale the result of the scattering phase function to get the final scattering factor.

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III. Volumetric Light (spot light) (with PCF shadow)

overview

cube	sphere	cone

camera movement	light adjustment

details

To make sure the volume will be rendered when the camera is inside of it, the culling mode is set to cull front face. To make sure the volume will be rendered when a object is inside of it, the depth test is disabled (as well as depth write). To get the correct enter and exit position of the ray intersecting the volume, (so that ray marching accumalates the correct amount of energy) the screen space depth is used to clamp the exit position and the camera position is used to clamp the enter position.

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IV. What's next?

• Dither Pattern & Up Sampling

• Full Screen Volume (Quad)

• More Light Types

  • Directional Light

  • Point Light

• More Shadow Techniques

  • Variance Shadow Map

  • Percentage Close Soft Shadow

• Some Clouds Rendering Experiments?