Compile shaders

Fix tiled rendering compositing in multicamera scenes https://i.imgur.com/wrqKgCO.png

Pass viewport offset to CDepthDownsampleLayerRenderer and offset it in the shader, fixes depth chain in multicamera scenes, always imply we're taking a full res downsample anyway

Fix formatting typo

Simplify and fix tiled light culling in corners, makes tiles match mipmapped depth fetch perfectly

Remove SetRenderAttributesForEnvironmentMap, Handshakes, ChooseEnvironmentMap and envmap bindings (cya), we're been GPU-driven for quite some time now Backport Texture Sets from Valve code drop, much saner way to work with textures of this kind ( EnvMap sheet, LightCookie sheet )

Strip out monitors, viewmodel and 3d skybox rendering paths from renderpipeline, needs to be cleared from the rest of the codebase (cherry pick from renderingpipeline_cleanup ) but if we don't do it now we never will RenderingPipelineVr becomes RenderingPipelineStandard Remove remaining non-VR "VR" references from rendering pipeline, remote retinaburn and env interaction system that have been never used for us, some more of VR stuff could be taken out now that we do it mostly all in managed Don't shrug off scratch render target system errors after a while

Clean compile shader with light edge fix

lit decal shader

Fix tiled rendering on 32x32 tiles https://files.facepunch.com/sam/1b1411b1/wzae5tFco9.png

Loop rather than unroll on fog lights, should give worse perf but fixes horrid startup times for now

Revert to shaders just before cascade/point light edge fix, needs a full compile which is already queued

Lightbinner Refactor (#1266) * Moved tiled rendering buffers to lightbinner, where it should belong * Remove members that have long been deprecated, start adding support for structured buffer lights * Move all cbuffer stuff to legacy, standard will only have structured buffer path * Start implementing structured buffer lights data structure * Remove all code for calculating mixed shadows, that'll be all allocated in the main light shadow function, iterate structured buffers * Iterate on new lightbinner, let all shadows render through a single rendering path, disregard legacy for now * Remove bMixed from LightEntry, it's complete bullshit, let static lights render only dynamic objects when doing shadows * Unified shadow casting, map indexed lights so we can fetch them easily and without needing to order sequentially, remove more deprecated stuff * Get rid of lightbinner_legacy completely * Eliminate legacy per view lighting constants, eliminate mixed shadows, add placeholder to some constants where they should belong * Cut more code from lightbinner light allocs, means only spots will alloc properly for now but cleans a lot of this, align cbuffers, add ComputeDirectLightingForLight to unify lighting calculation on shader * Remove CSunLightManager, used for old pre-hlvr sun rendering, a lot of code that's only used for dynamic sunlight different to everything else in light rendering * Remove more unused parameters from lightbinner * Remove remaining crumbs of old sun shadowing, remove unused shadow functions, add bBaked to ComputeDirectLightingForLight * Lightcookies and point lights * Remove multiview constants from lightbinner, these have been getting in my way, and we need to think a better way to handle instanced viewports, I'm leaving it to a bigger cleanup later * Start Envmap support on new lightbinner, remove unused environment_map.fxc * Start MATERIAL_LIGHT_DIRECTIONAL support for lightbinner, sets up frusta for lights * Fix conflicts from merge that added removed stuff * Fixup for directional lights, add dummy ambient lighting for fully dynamic scenes, implement flags properly * Fix merge ( g_nNumEnvMaps > NumEnvironmentMaps ) * Remove interface definition from Vfx ( It's fucked off from HLSL 2020+ ), add array support to members in classes in Vfx * Store multiple frusta on same light definition rather than using sequential lights, makes this simpler, point light shadows * Ambient light, new strategy for shadow frusta * Disable r_enable_high_precision_lighting, just ends up overcomplicating code, reevaluate if this actually affects much away from world origin, will make vPositionWithOffsetWs just become vPositionWs in shaders if fully removed * Take shadow frustra from BuildShadowFrustaForLight() that matches what's on the shadow map renderer, rather than rebuilding it with twice the code * Test of multiple frusta support for shadow maps on shader 🥳 * Support for cascaded shadow maps on new unified multi-frusta system, needs to backport old code * Backport directional CSM code to unified BuildShadowFrustraForDirectionalLight in lightdesc * Shadow filtering and dummy ambient lighting * Calculate spot light resolution proportionally based on light cone and do a LOD system for light shadows based on distance, both are meant to be perceptual https://files.facepunch.com/sam/1b1211b1/sbox_rl2LTOMdY4.mp4 * CSM Adjustments * Pass envmap data to GPU * Fixups for cubemaps on shader, add test for ambient light IBL support https://files.facepunch.com/sam/1b1311b1/ibl.png * We dont need start indexes for lights anymore, just remap the index for fog and baked, fixup envmap count to shader * Remove refs to CalculatePositionToCameraDirWsMultiview function call in new lightbinner shader code * Cleanup, remove a bunch of unused or deprecated shit, cleaned up a lot of variable in lightbinner structured buffer that ends up not being needed, document things a bit better * Rename lightconstants.hlsl to lightbinner.hlsl and call the data there BinnedLight/BinnedEnvMap, make baked lights only cast shadows if mixed lights are enabled on them * Fix flags on lightbinner gpu include, oops * Refactor tiled rendering builder to be compatible with new lightbinner, make it implicit under lightbinner.hlsl * Fog lights support, remove second buffer that's meant for fog lights, remove bullshit code to support old directional light from it that was just meant to be tools-only, all light types just works now https://files.facepunch.com/sam/1b2111b1/C3pY5Q7jq9.png * Fix directional light farz https://files.facepunch.com/sam/1b2111b1/Jn16Ruj0ub.png * Remove SetShadowCascadeResolution and SetShadowCascadeDistance, both pointless, cascades use shadow resolution, add SetCascadeDistanceScale, make number of cascade count actually work * Add g_vRandomFloats to replace oddly named ScreenSpaceDitherParams, fix reflections and volume fog using that * Rename Tiled Light Builder to Tiled Light Culling, do fixes for the new system and shrink tiles to 32x32 from 48x48, allowing us to just take a single fetch from depth buffer for GPU culling tests * Fix lightcookie support, add support for colors on indexed lights with lightcookies, remove lightcookie index from lightbinner.hlsl, just pass the transform https://files.facepunch.com/sam/1b2711b1/zTwJgEDa7N.jpg * Add unified Subsurface Scattering support for skin shadiing, previously every light type implemented this differently causing shading differences, now baked lights show this correctly too https://files.facepunch.com/sam/1b2711b1/k5L2Punaav.png * Readd SetShadowCascadeResolution and SetShadowCascadeDistance as stub obsolte methods to not break existing games * Finalize things, fix misc warnings, fix SSR and enable directional lightmaps * Unify Two Lobe Specular and normal Specular * Test: do full checkout with clean on shader.yml, delete debug_shaders.yml ( pointless ) * Pass skycolor of multiple lights to renderer, works with multiple lights, fixes skycolor attribute doing nothing, while it'd be nice to just pass envmap diffuse lighting for ambients right now it'd break some workflows * Fix typo on cloth shading combos * Remove references to removed files in shaders * CI: Use git checkout to remove stashed changes, shouldn't error if there are no changes to save & drop * debug_sunshadow_vis is gone, update all_shaders with what's actually there * Add LightSupportsTimeSlicedRendering and filter directional lights out of it, fixes cascades being fucked on hammer * Loop rather than unrolling CalculateLightingAtPoint, sucks for perfomance but this function shouldnt take start and end indexes of the light, focus on correctness first * Fix trunkation warning * Pass correct envmap index * Reenable high precision lighting, it's all fine now (but still considering removing it) * [ Pick ] remove specialized decal rendering path from skin * Fix cascade scale for maps that arent compiled with the new light attributes * Apply indirect transmissive lighting, previously would only be affectted by direct lighting * Migrate light api to new lightbinner system * Get light culling render buffer from rendercontext rather than from layer * Fix compilation of tiled_light_culling on vulkan (wtf?) * Transpose matrices on d3d11 * Support for multiple suns and fog on atmosphere_sky, code for this still sucks since this came from the first days of development * Remove decal references in skin shader, thought I had that sorted :S * Remove decal_renderer from allshaders.txt * Compile shaders * Refactor fog shader to take lights by index rather than by list, unroll loops still * Minor fixes, x.Load(i) and x[i] has different behaviour between vk and d3d11? Compiled lit user shaders * Shader CI: Do git clean before pull * Compile core shaders * Compile user shaders * Compiled light culling material * Add lightData.HasFrustumFeathering() for seamless fading between light cascades * Consider one texel from edge to be considered outside the shadow region so that multiple frusta won't do smooth sampling on edges * Consider cascade to always be squared * Compile shaders --------- Co-authored-by: Matt Stevens <matt@mattstevens.co.uk>

Set default render system to Vulkan 👌

Compile shaders

Moved tiled rendering buffers to lightbinner, where it should belong Remove members that have long been deprecated, start adding support for structured buffer lights Move all cbuffer stuff to legacy, standard will only have structured buffer path Start implementing structured buffer lights data structure Remove all code for calculating mixed shadows, that'll be all allocated in the main light shadow function, iterate structured buffers Iterate on new lightbinner, let all shadows render through a single rendering path, disregard legacy for now Remove bMixed from LightEntry, it's complete bullshit, let static lights render only dynamic objects when doing shadows Unified shadow casting, map indexed lights so we can fetch them easily and without needing to order sequentially, remove more deprecated stuff Get rid of lightbinner_legacy completely Eliminate legacy per view lighting constants, eliminate mixed shadows, add placeholder to some constants where they should belong Cut more code from lightbinner light allocs, means only spots will alloc properly for now but cleans a lot of this, align cbuffers, add ComputeDirectLightingForLight to unify lighting calculation on shader Remove CSunLightManager, used for old pre-hlvr sun rendering, a lot of code that's only used for dynamic sunlight different to everything else in light rendering Remove more unused parameters from lightbinner Remove remaining crumbs of old sun shadowing, remove unused shadow functions, add bBaked to ComputeDirectLightingForLight Lightcookies and point lights Remove multiview constants from lightbinner, these have been getting in my way, and we need to think a better way to handle instanced viewports, I'm leaving it to a bigger cleanup later Start Envmap support on new lightbinner, remove unused environment_map.fxc Start MATERIAL_LIGHT_DIRECTIONAL support for lightbinner, sets up frusta for lights Fix conflicts from merge that added removed stuff Fixup for directional lights, add dummy ambient lighting for fully dynamic scenes, implement flags properly Fix merge ( g_nNumEnvMaps > NumEnvironmentMaps ) Remove interface definition from Vfx ( It's fucked off from HLSL 2020+ ), add array support to members in classes in Vfx Store multiple frusta on same light definition rather than using sequential lights, makes this simpler, point light shadows Ambient light, new strategy for shadow frusta Disable r_enable_high_precision_lighting, just ends up overcomplicating code, reevaluate if this actually affects much away from world origin, will make vPositionWithOffsetWs just become vPositionWs in shaders if fully removed Take shadow frustra from BuildShadowFrustaForLight() that matches what's on the shadow map renderer, rather than rebuilding it with twice the code Test of multiple frusta support for shadow maps on shader 🥳 Support for cascaded shadow maps on new unified multi-frusta system, needs to backport old code Backport directional CSM code to unified BuildShadowFrustraForDirectionalLight in lightdesc Shadow filtering and dummy ambient lighting Calculate spot light resolution proportionally based on light cone and do a LOD system for light shadows based on distance, both are meant to be perceptual https://files.facepunch.com/sam/1b1211b1/sbox_rl2LTOMdY4.mp4 CSM Adjustments Pass envmap data to GPU Fixups for cubemaps on shader, add test for ambient light IBL support https://files.facepunch.com/sam/1b1311b1/ibl.png We dont need start indexes for lights anymore, just remap the index for fog and baked, fixup envmap count to shader Remove refs to CalculatePositionToCameraDirWsMultiview function call in new lightbinner shader code Cleanup, remove a bunch of unused or deprecated shit, cleaned up a lot of variable in lightbinner structured buffer that ends up not being needed, document things a bit better Rename lightconstants.hlsl to lightbinner.hlsl and call the data there BinnedLight/BinnedEnvMap, make baked lights only cast shadows if mixed lights are enabled on them Fix flags on lightbinner gpu include, oops Refactor tiled rendering builder to be compatible with new lightbinner, make it implicit under lightbinner.hlsl Fog lights support, remove second buffer that's meant for fog lights, remove bullshit code to support old directional light from it that was just meant to be tools-only, all light types just works now https://files.facepunch.com/sam/1b2111b1/C3pY5Q7jq9.png Fix directional light farz https://files.facepunch.com/sam/1b2111b1/Jn16Ruj0ub.png Remove SetShadowCascadeResolution and SetShadowCascadeDistance, both pointless, cascades use shadow resolution, add SetCascadeDistanceScale, make number of cascade count actually work Add g_vRandomFloats to replace oddly named ScreenSpaceDitherParams, fix reflections and volume fog using that Rename Tiled Light Builder to Tiled Light Culling, do fixes for the new system and shrink tiles to 32x32 from 48x48, allowing us to just take a single fetch from depth buffer for GPU culling tests Fix lightcookie support, add support for colors on indexed lights with lightcookies, remove lightcookie index from lightbinner.hlsl, just pass the transform https://files.facepunch.com/sam/1b2711b1/zTwJgEDa7N.jpg Add unified Subsurface Scattering support for skin shadiing, previously every light type implemented this differently causing shading differences, now baked lights show this correctly too https://files.facepunch.com/sam/1b2711b1/k5L2Punaav.png Readd SetShadowCascadeResolution and SetShadowCascadeDistance as stub obsolte methods to not break existing games Finalize things, fix misc warnings, fix SSR and enable directional lightmaps Unify Two Lobe Specular and normal Specular Test: do full checkout with clean on shader.yml, delete debug_shaders.yml ( pointless ) Pass skycolor of multiple lights to renderer, works with multiple lights, fixes skycolor attribute doing nothing, while it'd be nice to just pass envmap diffuse lighting for ambients right now it'd break some workflows Fix typo on cloth shading combos Remove references to removed files in shaders CI: Use git checkout to remove stashed changes, shouldn't error if there are no changes to save & drop debug_sunshadow_vis is gone, update all_shaders with what's actually there Add LightSupportsTimeSlicedRendering and filter directional lights out of it, fixes cascades being fucked on hammer Loop rather than unrolling CalculateLightingAtPoint, sucks for perfomance but this function shouldnt take start and end indexes of the light, focus on correctness first Fix trunkation warning Pass correct envmap index Reenable high precision lighting, it's all fine now (but still considering removing it) [ Pick ] remove specialized decal rendering path from skin Fix cascade scale for maps that arent compiled with the new light attributes Apply indirect transmissive lighting, previously would only be affectted by direct lighting Migrate light api to new lightbinner system Get light culling render buffer from rendercontext rather than from layer Fix compilation of tiled_light_culling on vulkan (wtf?) Transpose matrices on d3d11 Support for multiple suns and fog on atmosphere_sky, code for this still sucks since this came from the first days of development Remove decal references in skin shader, thought I had that sorted :S Remove decal_renderer from allshaders.txt Compile shaders Refactor fog shader to take lights by index rather than by list, unroll loops still Minor fixes, x.Load(i) and x[i] has different behaviour between vk and d3d11? Compiled lit user shaders Shader CI: Do git clean before pull Compile core shaders Compile user shaders Compiled light culling material Add lightData.HasFrustumFeathering() for seamless fading between light cascades Consider one texel from edge to be considered outside the shadow region so that multiple frusta won't do smooth sampling on edges Consider cascade to always be squared

Add lightData.HasFrustumFeathering() for seamless fading between light cascades

Compile user shaders

Compile core shaders

Shader CI: Do git clean before pull

Minor fixes, x.Load(i) and x[i] has different behaviour between vk and d3d11? Compiled lit user shaders

Refactor fog shader to take lights by index rather than by list, unroll loops still

Moved tiled rendering buffers to lightbinner, where it should belong Remove members that have long been deprecated, start adding support for structured buffer lights Move all cbuffer stuff to legacy, standard will only have structured buffer path Start implementing structured buffer lights data structure Remove all code for calculating mixed shadows, that'll be all allocated in the main light shadow function, iterate structured buffers Iterate on new lightbinner, let all shadows render through a single rendering path, disregard legacy for now Remove bMixed from LightEntry, it's complete bullshit, let static lights render only dynamic objects when doing shadows Unified shadow casting, map indexed lights so we can fetch them easily and without needing to order sequentially, remove more deprecated stuff Get rid of lightbinner_legacy completely Eliminate legacy per view lighting constants, eliminate mixed shadows, add placeholder to some constants where they should belong Cut more code from lightbinner light allocs, means only spots will alloc properly for now but cleans a lot of this, align cbuffers, add ComputeDirectLightingForLight to unify lighting calculation on shader Remove CSunLightManager, used for old pre-hlvr sun rendering, a lot of code that's only used for dynamic sunlight different to everything else in light rendering Remove more unused parameters from lightbinner Remove remaining crumbs of old sun shadowing, remove unused shadow functions, add bBaked to ComputeDirectLightingForLight Lightcookies and point lights Remove multiview constants from lightbinner, these have been getting in my way, and we need to think a better way to handle instanced viewports, I'm leaving it to a bigger cleanup later Start Envmap support on new lightbinner, remove unused environment_map.fxc Start MATERIAL_LIGHT_DIRECTIONAL support for lightbinner, sets up frusta for lights Fix conflicts from merge that added removed stuff Fixup for directional lights, add dummy ambient lighting for fully dynamic scenes, implement flags properly Fix merge ( g_nNumEnvMaps > NumEnvironmentMaps ) Remove interface definition from Vfx ( It's fucked off from HLSL 2020+ ), add array support to members in classes in Vfx Store multiple frusta on same light definition rather than using sequential lights, makes this simpler, point light shadows Ambient light, new strategy for shadow frusta Disable r_enable_high_precision_lighting, just ends up overcomplicating code, reevaluate if this actually affects much away from world origin, will make vPositionWithOffsetWs just become vPositionWs in shaders if fully removed Take shadow frustra from BuildShadowFrustaForLight() that matches what's on the shadow map renderer, rather than rebuilding it with twice the code Test of multiple frusta support for shadow maps on shader 🥳 Support for cascaded shadow maps on new unified multi-frusta system, needs to backport old code Backport directional CSM code to unified BuildShadowFrustraForDirectionalLight in lightdesc Shadow filtering and dummy ambient lighting Calculate spot light resolution proportionally based on light cone and do a LOD system for light shadows based on distance, both are meant to be perceptual https://files.facepunch.com/sam/1b1211b1/sbox_rl2LTOMdY4.mp4 CSM Adjustments Pass envmap data to GPU Fixups for cubemaps on shader, add test for ambient light IBL support https://files.facepunch.com/sam/1b1311b1/ibl.png We dont need start indexes for lights anymore, just remap the index for fog and baked, fixup envmap count to shader Remove refs to CalculatePositionToCameraDirWsMultiview function call in new lightbinner shader code Cleanup, remove a bunch of unused or deprecated shit, cleaned up a lot of variable in lightbinner structured buffer that ends up not being needed, document things a bit better Rename lightconstants.hlsl to lightbinner.hlsl and call the data there BinnedLight/BinnedEnvMap, make baked lights only cast shadows if mixed lights are enabled on them Fix flags on lightbinner gpu include, oops Refactor tiled rendering builder to be compatible with new lightbinner, make it implicit under lightbinner.hlsl Fog lights support, remove second buffer that's meant for fog lights, remove bullshit code to support old directional light from it that was just meant to be tools-only, all light types just works now https://files.facepunch.com/sam/1b2111b1/C3pY5Q7jq9.png Fix directional light farz https://files.facepunch.com/sam/1b2111b1/Jn16Ruj0ub.png Remove SetShadowCascadeResolution and SetShadowCascadeDistance, both pointless, cascades use shadow resolution, add SetCascadeDistanceScale, make number of cascade count actually work Add g_vRandomFloats to replace oddly named ScreenSpaceDitherParams, fix reflections and volume fog using that Rename Tiled Light Builder to Tiled Light Culling, do fixes for the new system and shrink tiles to 32x32 from 48x48, allowing us to just take a single fetch from depth buffer for GPU culling tests Fix lightcookie support, add support for colors on indexed lights with lightcookies, remove lightcookie index from lightbinner.hlsl, just pass the transform https://files.facepunch.com/sam/1b2711b1/zTwJgEDa7N.jpg Add unified Subsurface Scattering support for skin shadiing, previously every light type implemented this differently causing shading differences, now baked lights show this correctly too https://files.facepunch.com/sam/1b2711b1/k5L2Punaav.png Readd SetShadowCascadeResolution and SetShadowCascadeDistance as stub obsolte methods to not break existing games Finalize things, fix misc warnings, fix SSR and enable directional lightmaps Unify Two Lobe Specular and normal Specular Test: do full checkout with clean on shader.yml, delete debug_shaders.yml ( pointless ) Pass skycolor of multiple lights to renderer, works with multiple lights, fixes skycolor attribute doing nothing, while it'd be nice to just pass envmap diffuse lighting for ambients right now it'd break some workflows Fix typo on cloth shading combos Remove references to removed files in shaders CI: Use git checkout to remove stashed changes, shouldn't error if there are no changes to save & drop debug_sunshadow_vis is gone, update all_shaders with what's actually there Add LightSupportsTimeSlicedRendering and filter directional lights out of it, fixes cascades being fucked on hammer Loop rather than unrolling CalculateLightingAtPoint, sucks for perfomance but this function shouldnt take start and end indexes of the light, focus on correctness first Fix trunkation warning Pass correct envmap index Reenable high precision lighting, it's all fine now (but still considering removing it) [ Pick ] remove specialized decal rendering path from skin Fix cascade scale for maps that arent compiled with the new light attributes Apply indirect transmissive lighting, previously would only be affectted by direct lighting Migrate light api to new lightbinner system Get light culling render buffer from rendercontext rather than from layer Fix compilation of tiled_light_culling on vulkan (wtf?) Transpose matrices on d3d11 Support for multiple suns and fog on atmosphere_sky, code for this still sucks since this came from the first days of development Remove decal references in skin shader, thought I had that sorted :S Remove decal_renderer from allshaders.txt Compile shaders

Compile shaders

Remove decal_renderer from allshaders.txt

rename pipeline to renderingpipeline_standard Remove remaining VR references from pipeline, remove specialized viewmodel, monitor and 3d skybox rendering paths from it Remove scenemonitor and dota planar reflection stuff

Remove decal references in skin shader, thought I had that sorted :S

Support for multiple suns and fog on atmosphere_sky, code for this still sucks since this came from the first days of development

Get light culling render buffer from rendercontext rather than from layer Fix compilation of tiled_light_culling on vulkan (wtf?) Transpose matrices on d3d11

[pick] Delete Decal Renderer that's used on unused skin decal stuff

Fix cascade scale for maps that arent compiled with the new light attributes Apply indirect transmissive lighting, previously would only be affectted by direct lighting Migrate light api to new lightbinner system

[ Pick ] remove specialized decal rendering path from skin

Pass correct envmap index Reenable high precision lighting, it's all fine now (but still considering removing it)

Fix trunkation warning

Loop rather than unrolling CalculateLightingAtPoint, sucks for perfomance but this function shouldnt take start and end indexes of the light, focus on correctness first

Add LightSupportsTimeSlicedRendering and filter directional lights out of it, fixes cascades being fucked on hammer

debug_sunshadow_vis is gone, update all_shaders with what's actually there

CI: Use git checkout to remove stashed changes, shouldn't error if there are no changes to save & drop

Fix typo on cloth shading combos Remove references to removed files in shaders

Pass skycolor of multiple lights to renderer, works with multiple lights, fixes skycolor attribute doing nothing, while it'd be nice to just pass envmap diffuse lighting for ambients right now it'd break some workflows

Test: do full checkout with clean on shader.yml, delete debug_shaders.yml ( pointless )

Unify Two Lobe Specular and normal Specular

Remove SetRenderAttributesForEnvironmentMap, Handshakes, ChooseEnvironmentMap and envmap bindings (cya), we're been GPU-driven for quite some time now

Finalize things, fix misc warnings, fix SSR and enable directional lightmaps

Add unified Subsurface Scattering support for skin shadiing, previously every light type implemented this differently causing shading differences, now baked lights show this correctly too https://files.facepunch.com/sam/1b2711b1/k5L2Punaav.png Readd SetShadowCascadeResolution and SetShadowCascadeDistance as stub obsolte methods to not break existing games

Fix lightcookie support, add support for colors on indexed lights with lightcookies, remove lightcookie index from lightbinner.hlsl, just pass the transform https://files.facepunch.com/sam/1b2711b1/zTwJgEDa7N.jpg

Rename Tiled Light Builder to Tiled Light Culling, do fixes for the new system and shrink tiles to 32x32 from 48x48, allowing us to just take a single fetch from depth buffer for GPU culling tests

Add g_vRandomFloats to replace oddly named ScreenSpaceDitherParams, fix reflections and volume fog using that