Performance issue with DiffuseMap/DiffuseColor & directional light/shadow map

[andychase]

The bug is when two objects exist in the same viewport with two different material schemes fps goes from 60fps to 29fps (for me):

• Scene has directional light with a shadow map
• Scene has two objects: 1 object is DiffuseMap and the other is Diffuse (color)

Just copying over from Forum topic: http://hub.jmonkeyengine.org/t/settexture-diffusemap-way-faster-than-setcolor-diffuse/31066/3

Test case

See gist: https://gist.github.com/andychase/be168144ce117c653b5a

• Needs: Textures/planter.png
• press "Z" and "X" to switch on/off

Workaround

In the mean time you can use the DirectionalShadowFilter with a FilterPostProcessor. It doesn't exhibit the issue and you should have the same visual result.

[Nehon]

I've finally looked into this issue.
It's not really an issue between DiffuseColor or DiffuseMap. It's actually a quesiton of how many different materials there is in the scene.

The shadow processor gathers all the materials of the scene to assign the shadow paramters on each frame.
Obviously if there is only one material, it's faster than with several material.
So this issue is a inherent to how we gather and update materials' parameters for the shadow post pass.

This could be aleviated if we had a way to add custom global parameters.Not completely sure it would be faster, but at least it would avoid the material gathering phase.