Bake shadows?

[CHRIS.PI3]

Hi !
I have a project where I need to see if some surfaces are in shadow during the year .More specific I need to also be able
to judge how much in shadow they are , i.e. total black if they are >70% in shadow during the year and light grey if they are <5% of the time.I don't need radiosity or soft shadows just a light with the sunspot motion modifier.
I have thought of making an animation with shadow catcher on the surfaces I want to check , and then composite all the frames in PS with the appropriate blend mode ,but first I am not sure if it will work and second I don't have lightwave 11...
Another option is using nodes but I can't figure a way to keep externally the spot info i.e. , so it can be referenced later in another frame..
If anyone has come through this or knows any solution i 'd be thankful

Thanks
Chris

[Janusz Biela]

I am not sure I can help You with that. I think correct way should be:

1. Setup Sunsky Sun under Layout according to expected time and setup model in correct orientation.
2. Bake textures from Kray menu in Raytracing mode.

But really I never did that...only theoretically

[CHRIS.PI3]

Thanks,
My first thought was texture baking but it doesn't work if I blend all the frames in PS , that's why I mentioned shadow catcher so that I could have the fully rendered scene in the first layer and all the frames with shadows (shadow catcher) in blend above the first layer.
Anyway , a solution would be of tremendous help to any architect or engineer for everything involving the Sun (lighting , solar heating , greenhouses , PV etc)
There exists dedicated software but it's seperate for every application ,is usually expensive and probably far worse in it's raytracing engine (if you exclude lighting ,where professional programs are very accurate).

[Janusz Biela]

I can help you only from Kray side. If you are interested in how to make texture bake in Kray then I can prepare video tutorial. Actually I have an idea right now - how to improve this function: bake the texture with override mode. This will allow you to use this map as blending map (so you can even change the texture later and use this map in real time preview or fast Ray Tracing render in another software).

[CHRIS.PI3]

bake the texture with override mode

If I understand correctly this would allow i.e. the baked map of a later frame to blend (multiplied or added or whatever) with the saved map of a previous frame (and not overwrite it completely).If this is the case then it's exactly what I am looking for!

Thanks
Chris

[Janusz Biela]

I will prepare short tutorial for this (Just give me 1-3 days). You can do with this map whatever You want (if they have texture then better use this bake map as blending to simulate real Gi) Of course this system is good with a couple surfaces. In complex scene this will be nightmare to bake all surfaces. Another limit is that: you can not use dynamic or Ray Tracing light in that prepared scene (all lights must be off)

[CHRIS.PI3]

thanks!
looking forward to it

[Janusz Biela]

Here how to "bake"
Object scene+baked textures you can download from my page (without commercial textures).

[youtube]8-woUDviyN8[/youtube]

[CHRIS.PI3]

Thank you Janusz !
I 'll try to post a tutorial too , based on this.

[medzo]

wow, this is great!!! i wish that the preperation would be more automatic, seems like a lot of similar steps...