How to use properly "use irradiance map" in materials ?

[bigbossfr]

Hi,
I have some questions about this option on materials :

1) If i disable this option, my material will use brute force. Where can i set subdivs of my brute force if i use irradiance map ?

2) Workflow :
- renderLayer1 : i have a static geometry. I bake one irradiance map for my static geometry, with all characters hided.
- renderLayer2 : i unhide all characters, disable all "use irradiance map" option on all characters materials. I render.

The problem : the GI of my characters is not on my static geometry, but the GI of my static geometry is on characters.
How can i resolve this ? (the goal is to bake one time and one irradiance map of my static geometry, and use brute force for all animated objects)

If we can't actually, do we can resolve this (feature) ?

Thanks

[vlado]

1) If i disable this option, my material will use brute force. Where can i set subdivs of my brute force if i use irradiance map ?

The hemispheric subdivs of the irradiance map are used.

The problem : the GI of my characters is not on my static geometry, but the GI of my static geometry is on characters.
How can i resolve this ? (the goal is to bake one time and one irradiance map of my static geometry, and use brute force for all animated objects)

Some people just use an AO pass for the contact shadows; not ideal, but usually no-one will notice.

I'm not sure what would be the perfect way to solve this (other than brute-forcing everything, of course).

Best regards,
Vlado

[bigbossfr]

The hemispheric subdivs of the irradiance map are used.

It is possible to separate the subdivs of the brute force and the irradiance map ?
Because if i set my subdivs of my IR to 120, i will set my subdivs of my BF (on characters) to 120 also ?

Some people just use an AO pass for the contact shadows; not ideal, but usually no-one will notice.

I'm not sure what would be the perfect way to solve this (other than brute-forcing everything, of course).

Best regards,
Vlado

It will be great if we can solve this. It will be a very great workflow.

[vlado]

It is possible to separate the subdivs of the brute force and the irradiance map ?
Because if i set my subdivs of my IR to 120, i will set my subdivs of my BF (on characters) to 120 also ?

Yes, but since you normally compute these in two separate passes, it is not a problem to change the value in between.

Best regards,
Vlado

[bigbossfr]

Yes, but since you normally compute these in two separate passes, it is not a problem to change the value in between.

Best regards,
Vlado

When you say : "you normally compute these in two separate passes", you want to say :
1) I render my static geometry
2) I render my characters
?

If yes, my goal is to render all of this into one pass, and use IR for my static geometry.

Because if i render this into 2 passes, i will use directly BF GI for my second pass .

[vlado]

Hm, but it doesn't make much sense to do that in one pass - you might still get flickering on the static geometry especially if the camera moves; plus, you will be recomputing the same thing over and over again.

Best regard,
Vlado

[Morbid Angel]

Vlado, what about having an option on geometry to generate only brute force gi even if irmap is used. For his scene, he can just enable this option and run his irmap for the render, but the moving geometry which will have this enabled will not get any irmap gi and not cast and irmap gi, and instead will get bruteforce gi during rendering of actual image?

[vlado]

The problem is not on the moving geometry, but on the static geometry that has contact shadows/color bleeding from moving objects. If we need to brute force those objects too, then I'm not sure what's the point of the whole exercise.

Best regards,
Vlado

[Adbk]

In my experience you'd want to render the characters separate from the BG and cheat the GI contact points of the char/BG with an AO pass as was suggested. It's good to have those split out and controllable from the rest of the GI anyways, and will be a more economic render in the long run...

cheers

[Morbid Angel]

The problem is not on the moving geometry, but on the static geometry that has contact shadows/color bleeding from moving objects. If we need to brute force those objects too, then I'm not sure what's the point of the whole exercise.

Essentially what I am suggesting is the sphere fade volume effect (like in that tutorial you wrote on spot3d.) but as one pass/option rather then few separate layers. I realize that tracing true gi rays from moving geometry is not possible to achieve in as fast as irradiance map way but if you would be able to do a blend like approach where the irmap samples stop and brute force sample start based on the radius of lets say bounding box of the geometry which was specified to be rendered as brute force then this should work (In my opinion anyway)