// RenderDepthPrepass render both opaque and opaque alpha tested based on engine configuration.
// Forward only renderer: We always render everything
// Deferred renderer: We render a depth prepass only if engine request it. We can decide if we render everything or only opaque alpha tested object.
// Forward opaque with deferred renderer (ForwardOnlyOpaqueDepthOnly pass): We always render everything
// Forward opaque with deferred renderer (DepthForwardOnly pass): We always render everything
// Guidelines: To be able to switch from deferred to forward renderer we need to have forward opaque material with both DepthOnly and ForwardOnlyOpaqueDepthOnly pass.
// This is also required if we want to support optional depth prepass dynamically.
// This is what is assume here. But users may want to reduce number of shader combination once they have made their choice.
// In case of deferred renderer, we can have forward opaque material. These materials need to be render in the depth buffer to correctly build the light list.
// And they will tag the stencil to not be lit during the deferred lighting pass.
// In case of forward only renderer we have a depth prepass. In case of deferred renderer, it is optional
// In case of deferred renderer, we can have forward opaque material. These materials need to be render in the depth buffer to correctly build the light list. And they will tag the stencil to not be lit during the deferred lighting pass.
// Caution: If a DepthPrepass is enabled for deferred then the object will be rendered with the pass DepthPrepass. See guidelines. This allow to switch dynamically between both mode.
// So we don't need to render the ForwardOnlyOpaqueDepthOnly pass
// Guidelines: In deferred by default there is no opaque in forward. However it is possible to force an opaque material to render in forward
// by using the pass "ForwardOnly". In this case the .shader should not have "Forward" but only a "ForwardOnly" pass.
// It must also have a "DepthForwardOnly" and no "DepthOnly" pass as forward material (either deferred or forward only rendering) have always a depth pass.
// We render first the opaque object as opaque alpha tested are more costly to render and could be reject by early-z (but not Hi-z as it is disable with clip instruction)
// This is handeled automatically with the RenderQueue value (OpaqueAlphaTested have a different value and thus are sorted after Opaque)
// Note: addDepthPrepass and addForwardOnlyOpaqueDepthPrepass can't be both true at the same time. And if we are here both are not false
if(addFullDepthPrepass&&!addAlphaTestedOnly)// Always true in case of forward rendering, use in case of deferred rendering if requesting a full depth prepass
{
// We render first the opaque object as opaque alpha tested are more costly to render and could be reject by early-z (but not Hi-z as it is disable with clip instruction)
// This is handled automatically with the RenderQueue value (OpaqueAlphaTested have a different value and thus are sorted after Opaque)
// Guidelines: To be able to switch from deferred to forward renderer we need to have forward opaque material with both Forward and ForwardOnlyOpaque pass.
// This is what is assume here. But users may want to reduce number of shader combination once they have made their choice.
// If we are transparent, we add the forward pass. Else (Render Opaque) we add it only if we are forward rendering
// Guidelines: In deferred by default there is no opaque in forward. However it is possible to force an opaque material to render in forward
// by using the pass "ForwardOnly". In this case the .shader should not have "Forward" but only a "ForwardOnly" pass.
// It must also have a "DepthForwardOnly" and no "DepthOnly" pass as forward material (either deferred or forward only rendering) have always a depth pass.
// The RenderForward pass will render the appropriate pass depends on the engine settings. In case of forward only rendering, both "Forward" pass and "ForwardOnly" pass
// material will be render for both transparent and opaque. In case of deferred, both path are used for transparent but only "ForwardOnly" is use for opaque.
// (Thus why "Forward" and "ForwardOnly" are exclusive, else they will render two times"
// In case of deferred we can still have forward opaque object
// It mean that addForwardOnlyOpaquePass = !addForwardPass which is a simplification of: renderOpaque && !m_Asset.renderingSettings.ShouldUseForwardRenderingOnly()
// There is no need to store this case as we don't need to test for it
// Forward opaque material always have a prepass (whether or not we use deferred, whether or not there is option like alpha test only) so we pass the right depth state here.
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7 年前