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Question: Environment map and sun

Posted: Sat Feb 19, 2011 6:43 am
by Alex Pisarev
Hi everyone!

Just wondering could it be possible to use env map and sketchup sun together anyhow or it`s basically impossible. Maybe somebody knows how to get an effect of sun shadows with environment map another way? thanks anyway)

Re: Question: Environment map and sun

Posted: Sat Feb 19, 2011 9:38 am
by CTZn
Hi Alex, Indigo can currently account for one single environment method at a time.

Generally speaking, getting more pronounced shadows from an environment map is a matter of dynamic range. In other words, the texture controls should allow you to set the dark zones of a lower energy than they are by default, and reversely for the brighter point (sun eventually). It is a mean to increase the hdr "contrast" without editing the image itself.

I'll let SkIndigo users tell you how :)

Re: Question: Environment map and sun

Posted: Sat Feb 19, 2011 9:48 am
by StompinTom
Or make a small meshlight far from your scene and crank the brightness so it's as bright as the sun!

Re: Question: Environment map and sun

Posted: Sun Feb 20, 2011 12:59 am
by Alex Pisarev
Thx for advice and explanation guys! It realy helps! :P i thought maybe there is something i dont know about skindigo.. but it could be a great feature to use this 2 things in couple anyway i think :roll:

Re: Question: Environment map and sun

Posted: Sun Feb 20, 2011 9:16 am
by Soup
StompinTom wrote:Or make a small meshlight far from your scene and crank the brightness so it's as bright as the sun!
Would this make a sun as good as sun & sky? If so, it could be a straight-forward hack for the exporter devs be to add a 'add sun object' tool - simply adds a small bright sphere just within the env sphere.

Although, sun light is all mostly parallel so I guess an emitter wouldn't quite have the same effect..

Re: Question: Environment map and sun

Posted: Sun Feb 20, 2011 9:42 am
by galinette
As envmap is a material that you may define with shaders, it could be possible to "add" a sun disc in the envmap during export. However, I think that Indigo will not sample the resulting envmap efficiently and this will be quite noisy.

Other solution would be "envmap prebaking" done by the exporter : add a sun disk in the envmap.

Etienne

Re: Question: Environment map and sun

Posted: Sun Feb 20, 2011 12:39 pm
by Soup
galinette wrote:Other solution would be "envmap prebaking" done by the exporter : add a sun disk in the envmap.

Etienne
Might be the easiest way I suppose. The exporters would need access to a bitmap library though. It would be easier if the baking could be done in Indigo, as defined by exported parameters...

Re: Question: Environment map and sun

Posted: Sun Feb 20, 2011 9:42 pm
by galinette
Or an option to pre-bake an envmap defined in ISL?

If you consider adding a feature to Indigo, having the option to add the sunlight to the envmap would be even more simple I think. Then just add the sun, not the sky.

More generally, why not allowing multiple environments? Indigo would just add their intensities (which is very simple for making importance sampling). This should be very easy to implement. That's, I suppose, what Indigo is already doing with the skylight environment, as it is separated in two components (sun and sky) that you can map in two separate light layers.

Etienne

Re: Question: Environment map and sun

Posted: Wed Feb 23, 2011 1:22 am
by galinette
Hey, what about this last proposal? I'm sure this is quite simple to implement "additive environments" in Indigo, as it is already doing it for sky+sun... This would allow very interesting environment combinations, such as hdri+sun

Etienne

Re: Question: Environment map and sun

Posted: Wed Feb 23, 2011 5:33 am
by Alex Pisarev
Hey, what about this last proposal? I'm sure this is quite simple to implement "additive environments" in Indigo, as it is already doing it for sky+sun... This would allow very interesting environment combinations, such as hdri+sun

Etienne
+1
That`s what I`m talking about!! :P