Huge performance drop with Eevee under certain conditions #64458

New Issue

lucas veber · 2019-05-10T22:29:47+02:00

lucas veber commented

2019-05-10 22:29:47 +02:00

System Information
Operating system: Windows-10-10.0.17134 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 419.67

Blender Version
Broken: version: 2.80 (sub 59), branch: Unknown, commit date: Unknown Unknown, hash: rBUnknown
Worked: (optional)

Short description of error
Eevee is very slow under unexpected conditions.

Exact steps for others to reproduce the error
In the attached scene, rendering with Eevee is slow (press spacebar to playback and see the fps in the top left corner).
Open this blend and switch to render mode. It contains 5 coconut trees only.
coconuts.blend

Weirdly, by doing one of the following operation listed below, the fps suddenly jumps from 4fps to 40-60fps.

Unplug the "Normal Map" node on the right from the "Diffuse BSDF" node next to it.
Remove the "coconut_trunk" material slot from the active object, the palms. Note this material is useless, it's not assigned to any faces. However it seems it's still evaluated in the loop, causing important slowdown.
Remove the "Wave" modifier from all palms objects.

**System Information** Operating system: Windows-10-10.0.17134 64 Bits Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 419.67 **Blender Version** Broken: version: 2.80 (sub 59), branch: Unknown, commit date: Unknown Unknown, hash: `rBUnknown` Worked: (optional) **Short description of error** Eevee is very slow under unexpected conditions. **Exact steps for others to reproduce the error** In the attached scene, rendering with Eevee is slow (press spacebar to playback and see the fps in the top left corner). Open this blend and switch to render mode. It contains 5 coconut trees only. [coconuts.blend](https://archive.blender.org/developer/F7026135/coconuts.blend) Weirdly, by doing one of the following operation listed below, the fps suddenly jumps from 4fps to 40-60fps. 1. Unplug the "Normal Map" node on the right from the "Diffuse BSDF" node next to it. 2. Remove the "coconut_trunk" material slot from the active object, the palms. Note this material is useless, it's not assigned to any faces. However it seems it's still evaluated in the loop, causing important slowdown. 3. Remove the "Wave" modifier from all palms objects.

lucas veber commented

2019-05-10 22:29:47 +02:00

Added subscriber: @LucasVeber

Marco commented

2019-05-14 13:32:42 +02:00

Added subscriber: @nacioss

Marco commented

2019-05-14 13:32:42 +02:00

Yeah, i can reproduce the issue

Ovionis commented

2019-05-14 14:05:04 +02:00

Added subscriber: @Phigon

Ovionis commented

2019-05-15 00:10:10 +02:00

The Normal Map has a performance leak on dense meshes, and leaks even if said mesh, does not have the material with it assigned to anything.

I increased my fps (with my scene) in eevee from 3 fps to around 30 fps, by muting the normal map node from their materials.
There were no textures in it, it was just there to make adding a texture faster if I needed to.

The Normal Map has a performance leak on dense meshes, and leaks even if said mesh, does not have the material with it assigned to anything. I increased my fps *(with my scene)* in eevee from **3 fps** to around **30 fps**, by muting the normal map node from their materials. There were no textures in it, it was just there to make adding a texture faster if I needed to.

Clément Foucault was assigned by Sebastian Parborg

2019-06-11 15:41:51 +02:00

Ben commented

2019-06-17 10:25:55 +02:00

Added subscriber: @TheOldBen

Ben commented

2019-06-17 10:25:55 +02:00

As a temporary workaround, we use a script to mute the normal nodes, which gives regular viewport performance and another to un-mute the nodes later for rendering:

Mute Nodes:

import bpy
for mat in bpy.data.materials:
    mat_node = mat.node_tree.nodes
    for node in mat_node:
        if isinstance(node, bpy.types.ShaderNodeNormalMap):
            node.mute = True

Un-Mute Nodes

import bpy
for mat in bpy.data.materials:
    mat_node = mat.node_tree.nodes
    for node in mat_node:
        if isinstance(node, bpy.types.ShaderNodeNormalMap):
            node.mute = False

As a temporary workaround, we use a script to mute the normal nodes, which gives regular viewport performance and another to un-mute the nodes later for rendering: Mute Nodes: ``` import bpy for mat in bpy.data.materials: mat_node = mat.node_tree.nodes for node in mat_node: if isinstance(node, bpy.types.ShaderNodeNormalMap): node.mute = True ``` Un-Mute Nodes ``` import bpy for mat in bpy.data.materials: mat_node = mat.node_tree.nodes for node in mat_node: if isinstance(node, bpy.types.ShaderNodeNormalMap): node.mute = False ```

Clément Foucault commented

2019-06-17 10:32:48 +02:00

Changed status from 'Open' to: 'Archived'

Clément Foucault closed this issue

2019-06-17 10:32:48 +02:00

Clément Foucault commented

2019-06-17 10:32:48 +02:00

This is because we recalculate the tangent space if the mesh changes. There is no workaround because normalmaps uses it. Realtime engines assume the tangents do not change and use GPU skinning, 2 things we cannot do in a program in blender (at least without special cases that are going to tangle everything).

Ben commented

2019-08-14 09:22:23 +02:00

Made an add-on that does the toggling, aptly named: Toggle Normal Maps
https://github.com/theoldben/ToggleNormalMaps

Made an add-on that does the toggling, aptly named: Toggle Normal Maps https://github.com/theoldben/ToggleNormalMaps

lucas veber commented

2019-09-04 11:04:52 +02:00

In #64458#752624, @TheOldBen wrote:
Made an add-on that does the toggling, aptly named: Toggle Normal Maps
https://github.com/theoldben/ToggleNormalMaps

Thanks for sharing!

Realtime engines assume the tangents do not change and use GPU skinning

@fclem Are there any plans for such optimizations? Would be a game changer, even if it's scheduled for Blender 3.0. Thanks for your work!

> In #64458#752624, @TheOldBen wrote: > Made an add-on that does the toggling, aptly named: Toggle Normal Maps > https://github.com/theoldben/ToggleNormalMaps Thanks for sharing! > Realtime engines assume the tangents do not change and use GPU skinning @fclem Are there any plans for such optimizations? Would be a game changer, even if it's scheduled for Blender 3.0. Thanks for your work!

Ben commented

2019-11-20 16:53:02 +01:00

There has been an alternate solution suggested here:
https://blenderartists.org/t/way-faster-normal-map-node-for-realtime-animation-playback-with-tangent-space-normals/1175379/3

We made an addon to replace Normal Map Nodes with the above-mentioned setup and return them back to normal with a toggle button for render time.
This add-on is available free of charge here:
https://github.com/theoldben/BlenderNormalGroups

There has been an alternate solution suggested here: https://blenderartists.org/t/way-faster-normal-map-node-for-realtime-animation-playback-with-tangent-space-normals/1175379/3 We made an addon to replace Normal Map Nodes with the above-mentioned setup and return them back to normal with a toggle button for render time. This add-on is available free of charge here: https://github.com/theoldben/BlenderNormalGroups ![Node_Toggle_Interface.gif](https://archive.blender.org/developer/F8148259/Node_Toggle_Interface.gif)

lucas veber commented

2019-11-20 18:49:15 +01:00

Thanks a lot for mentioning it, this is more than welcome! Will make happy thousand of users.

Alan Knittel commented

2023-07-29 22:40:13 +02:00

Has this been addressed in some way in Blender 3,6 so we dont have to toggle this, even with this very nice add-on?

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Huge performance drop with Eevee under certain conditions #64458