GPU Functional Level

HOOPS Luminate has a number of built-in advanced rendering features in its core real-time engine (shadows, HDR pipeline, GPU ray-tracing, etc…). Therefore, the HOOPS Luminate API adds a RED::HARDWARE_PLATFORM enumeration aiming at defining a classification of all graphic cards known by HOOPS Luminate. Each card identified by the RED::IGraphicDevice interface services has a RED::HARDWARE_PLATFORM tag set in its RED::GPUID structure.

Hardware Functional Level Matrix

The picture below summarizes the different HOOPS Luminate rendering features and the possible support of each for each kind of graphic card:

../../../../_images/gpu_functional_level.png

HOOPS Luminate real-time rendering functions available for different kind of hardware

Notes:

    1. Among RED::HW_INTEL_GMA_3000 cards, those that are using the 14.32.4.4926 driver (or 14.32.4.64.4926 for x64 OS) have no support for RED::TGT_TEX_RECT textures. All others (INTEL Q33 and above references) have a complete support for the rectangle textures. This lack of support for the rectangular textures is very problematic and deeply limits the HOOPS Luminate hardware capabilities on these hardware (multiple VRLs using RECT render images are not possible for instance). HOOPS Luminate internally replaces all RECT textures sampling orders by simple color assignments to let shaders run, but this can’t replace the real result.

    1. Engine anti-aliasing, composite images and shadow maps are available on RED::HW_INTEL_GMA_GEN7 hardware. However, due to driver issues, rendering artifacts may appear after window resize operations.

    1. On RED::HW_ATI_R300 chipsets, the engine anti-aliasing level is at most x4 (16 sub-samples per pixel). The hardware can’t display a more precise AA.

    1. Legacy ATI hardware have an upper limit for the shadow map blur radius. RED::HW_ATI_R300: 1; RED::HW_ATI_R400: 3; RED::HW_ATI_R500: 5; RED::HW_ATI_R600: 14. All newer ATI cards have no limit in the shadow map blur radius setting.

Each feature, if not supported by the used hardware has a fallback. The list of fallbacks is here for each missing feature:

  • RECT textures: All texture sampling orders are replaced by a copy of a white color in the result.

  • Engine AA: The image is rendered without anti-aliasing.

  • Float and half-float texture formats: Textures are converted to their LDR equivalent format (LDR = Low Dynamic Range: for example, RED::FMT_FLOAT_RGBA becomes RED::FMT_RGBA).

  • Float and half-float HDR option: The option value is ignored. The rendering remains LDR.

  • Float and half-float support with software ray-tracer anti-aliasing. The rendered image is turned into a LDR image before tone-mapping is applied.

  • Composite images: Composite images are all black.

  • Native HDR: The buffer format is internally set to a LDR equivalent format.

  • Shadow map: No shadows are being cast.

  • Ray-traced shadows: No shadows are being cast.

  • Ray-traced reflections & refractions: No reflections or refractions are being cast.

  • Area lighting and shadows: Centric lighting models are used instead.

  • Ray-traced glossiness: No reflections or refractions are being cast.