Limitations

Eevee’s goal is to be an interactive render engine. Some features may not be there yet or may be impossible to implement into Eevee’s architecture without compromising performance.

Here is a rather exhaustive list of all the limitations you can expect while working with Eevee.

Cameras

Seulement les projections perspective et orthographique sont actuellement prises en charge.

Lights

Only 128 active lights can be supported by Eevee in a scene.
Only 8 Shadowed sun lights can be supported at the same time.
As of now, lights can only have one color and do not support light node trees.

Sondes de lumières

Eevee only supports up to 128 active Reflection Cubemaps.
Eevee only supports up to 64 active Irradiance Volumes.
Eevee only supports up to 16 active Reflection Planes inside the view frustum.

Lumière indirecte

Volumetrics don’t receive light from Irradiance Volumes but do receive world’s diffuse lighting.
Eevee does not support « specular to diffuse » light bounces nor « specular to specular » light bounces.
All specular lighting is turned off during baking.

Shadows (ombres)

Only 128 active lights can be supported by Eevee in a scene.
Only 8 Shadowed sun lights can be supported at the same time.

Volumetrics (Volumétriques)

Seulement single scattering est pris en charge.
Les volumétriques ne sont l’objet d’un rendu que pour les “rayons” de la caméra. Ils n’apparaissent pas dans les réflexions/réfractions et dans les sondes.
Volumetrics don’t receive light from Irradiance Volumes but do receive diffuse lighting from the world.
L’ombrage volumétrique ne fonctionne que sur d’autres volumétriques. Ils ne vont pas projeter des ombres sur des objets solides dans la scène.
L’ombrage volumétrique ne fonctionne que pour les volumes se trouvant dans le view frustum.
Volumetric lighting do not respect the lights shapes. They are treated as point lights.

Depth Of Field (Profondeur de champ)

Alpha blended surfaces cannot be correctly handled by the post-processing blur, but will be correctly handled by the sample-based method. For this, you need to disable the post-process depth of field by setting the Max Size to 0.

Screen Space Effects (Effets d’espace d’écran)

Eevee is not a ray tracing engine and cannot do ray-triangle intersection. Instead of this, Eevee uses the depth buffer as an approximated scene representation. This reduces the complexity of scene scale effects and enables a higher performance. However, only what is in inside the view can be considered when computing these effects. Also, since it only uses one layer of depth, only the front-most pixel distance is known.

Ces limitations posent quelques problèmes :

Les effets d’espace d’écran disparaissent lorsque vous atteignez la bordure de l’écran. Cela peut être partiellement corrigé en utilisant la fonction overscan.
Les effets d’espace d’écran manquent d’informations profondes (ou d’épaisseur des objets). C’est pourquoi la plupart des effets ont un paramètre d’épaisseur pour contrôler la façon de considérer les pixels potentiels intersectés.
Les surfaces mélangées ne sont pas prises en compte par ces effets. Ils ne font pas partie de la passe de profondeur préalable (depth prepass) et n’apparaissent pas dans le tampon de profondeur.
Les objets qui font partie de Holdout Collections ne seront pas rendus avec les effets d’espace d’écran.

Ambient Occlusion (Occlusion ambiante)

Objects are treated as infinitely thick, producing overshadowing if the Distance is really large.

Screen Space Reflections

Only one glossy BSDF can emit screen space reflections.
The evaluated BSDF is currently arbitrarily chosen.
Screen Space Reflections will reflect transparent objects and objects using Screen Space Refraction but without accurate positioning due to the one layer depth buffer.

Screen Space Refraction

Only one refraction event is correctly modeled.
Only opaque and alpha hashed materials can be refracted.

Subsurface Scattering (Transluminescence)

Only one BSSRDF can produce screen space subsurface scattering.
The evaluated BSSRDF is currently arbitrarily chosen.
A maximum of 254 different surfaces can use subsurface scattering.
Only scaling is adjustable per pixel. Individual RGB radii are adjustable in the socket default value.
Input radiance from each surfaces are not isolated during the blurring, leading to light leaking from surface to surface.

Motion Blur (flou de mouvement)

Motion Blur is only available in final renders and is not shown in the 3D Viewport and thus Viewport Renders.

Materials

Refractions

Refraction is faked by sampling the same reflection probe used by the Glossy BSDFs, but using the refracted view direction instead of the reflected view direction. Only the first refraction event is modeled correctly. An approximation of the second refraction event can be used for relatively thin objects using Refraction Depth. Using Screen Space refraction will refract what is visible inside the view, and use the nearest probe if there is no hit.

Screen Space Reflections and Ambient Occlusion are not compatible with Screen Space Refraction; they will be disabled on the surfaces that use it. Surfaces that use Screen Space Refraction will not appear in Screen Space Reflections at the right place. Surfaces that use Screen Space Refraction will not cast Ambient Occlusion onto other surfaces.

Volume Objects

Object volume shaders will affect the whole bounding box of the object. The shape of the volume must be adjusted using procedural texturing inside the shader.

Les nœuds Shader

All BSDF’s are using approximations to achieve realtime performance so there will always be small differences between Cycles and Eevee.
Some utility nodes are not yet compatible with Eevee (e.g. Sky Texture node).

Voir aussi

For a full list of unsupported nodes see Nodes Support.

Gestion de la mémoire

In Eevee, GPU Memory management is done by the GPU driver. In theory, only the needed textures and meshes (now referred as « the resources ») for a single draw call (i.e. one object) needs to fit into the GPU memory.

Aussi si la scène est réellement lourde, le pilote va interchanger les choses pour s’assurer que tous les objets sont rendus correctement.

En pratique, l’utilisation de trop de mémoire GPU peut faire planter le pilote GPU, ou tuer l’application. Aussi soyez prudent avec ce que vous demandez.

Il n’existe pas de manière standard pour estimer si les ressources vont tenir dans la mémoire GPU et/ou si le GPU va réussir à en faire le rendu.

Rendu CPU

Being a rasterization engine, Eevee only uses the power of the GPU to render. There is no plan to support CPU (software) rendering as it would be very inefficient. CPU power is still needed to handle high scene complexity as the geometry must be prepared by the CPU before rendering each frame.

Prise en charge de plusieurs GPU

Il n’y a actuellement pas de prise en charge pour des systèmes à GPU multiples.

Rendu sans affichage

There is currently no support for using Eevee on headless systems (i.e. without a Display Manager).

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