How can I render the shadow mapping texture only once?

[BlackMojito]

Hi guys,

I have a static scene with fixed meshes and a fixed spot light for shadow mapping. So theoretically I can render the shadow map only once. How can I do it in Babylon?

[Amarth2Estel]

Hello BlackMojito !

I copy-paste below a part of : https://doc.babylonjs.com/babylon101/shadows
This is a very interesting page where you can find almost all the possibilities about shadows.

 

Freezing shadows in static world

In case you have a static game world (objects which cast shadows) - there is no need to do the same shadow calculations 60 times per second. It could be enough to create and place a shadowMap only once. This greatly improves performance, allowing higher values of shadowMap's resolution.

Shadow generators can be frozen with:

shadowGenerator.getShadowMap().refreshRate = BABYLON.RenderTargetTexture.REFRESHRATE_RENDER_ONCE;

Ask the light to not recompute shadow position with:

light.autoUpdateExtends = false;

[BlackMojito]

30 minutes ago, Amarth2Estel said:

Hello BlackMojito !

I copy-paste below a part of : https://doc.babylonjs.com/babylon101/shadows
This is a very interesting page where you can find almost all the possibilities about shadows.

 

Freezing shadows in static world

In case you have a static game world (objects which cast shadows) - there is no need to do the same shadow calculations 60 times per second. It could be enough to create and place a shadowMap only once. This greatly improves performance, allowing higher values of shadowMap's resolution.

Shadow generators can be frozen with:

shadowGenerator.getShadowMap().refreshRate = BABYLON.RenderTargetTexture.REFRESHRATE_RENDER_ONCE;

Ask the light to not recompute shadow position with:

light.autoUpdateExtends = false;

I tried. But in my case, I can encounter the fact that my meshes/materials are not ready (isReady return false) yet when the first time the shadoow RenderTargetTexture._shouldRender() returns true.  And...as you know it will never return true again...

[BlackMojito]

The case is that my model is downloaded from the server When the mesh creation stuff is completed (added to their parent node,  materials assigned, etc.), I get a message. At that moment I create the shadow generator and set the refresh rate to be ONCE. But then I get meshes which are not ready...

[BlackMojito]

Oh I am sorry, I forgot to call addShadowCaster before the first call of _shouldRender(). Sorry for the noise...