How to use three image sIBL type rendering in blender (now with example blend).

A tutorial on how to set up image based rendering with separate images for lighting, reflections and background so the scene be rendered in one render with blenders internal renderer.

http://www.subcult.org/lahlab/blender/el.html

server connection is slow so images may load slowly.

My first blender tutorial so be nice…

Now it contains a downloadable exampel blend that use IBL and sss. Some renders:

Attachments



Thanks for the 3 image lighting tutorial LaH, I’ve been wanting to learn how to do this.

I have a question that’s on a side-note but relevant to this type of setup.

If you were to place an invisible ground plane, set to ‘ShadowsOnly’ so that your objects cast a shadow – is there any way to get this setup to work with mirrors? I can get objects in the scene to cast shadows onto the invisible ground plane. Even AO seems to be working, but any material with mirror reflects the ground plane as black. I’ve tried every switch in the Materials and Textures panels I can find, but no luck. I haven’t tried to solve it with render layers and object passes (still trying to learn that stuff). Is this a limitation of Blender at the moment or have I missed something simple?

I’m still close to noob on blender. I just, due to other experiment at the same time, found a solution to this problem when it came up in discussion threads on HDR lighting tutorials. So I investigated it further to find most gotchas and wrote this tut - You don’t get that many chances to contribute when You almost a noob :slight_smile:

But some speculations:

The switch I would try is traceable under options on material… but…

If You want to throw shadows on an invisible plane it’s because You want to overlay Your render over a background image that Your render should melt in to and be a part of (I guess). In that case You in deep trouble with a mirror anyway as You want it to reflect that environment You only have as a flat image.

So You need to render the mirroring in an environment with the background projected on some environment geometry anyway - this tut might help http://www.blenderguru.com/camera-mapping/ a bit.

Alternatively, if it’s a still at least, You may hand edit the reflections in after the rendering. Maybe thats why blender render it black, so You can know where to edit those reflections in.

But it might be a shortcoming to, raytrace mirror have some limits and I have not nailed them yet - I still get surprised at times.

EDIT: Blender might also do the expected thing and not showing that plain in the reflection if You have an transparent background on Your render, because there is absolutely no sane way blender can render ‘transparency’ on to a reflection so it just have to do something.

Very good tut and explanations!

Thanks!

Much thanks /LaH

Very comprehensive tutorial - Thank You!

I do have a question though - is it possible to render my own angular hdrs out with blender (or do I have to shoot a mirror ball and convert it with qtpfsgui/luminace hdr to angular)?

If You shoot with a mirror ball You more or less get a angmap projection so that should be fine to use for lighting (but You need to convert it to polar for the reflection and background with qtpfsgui/luminace)

If You have a polar image You can convert it with qtpfsgui/luminace to angmap for the lighting.

I have not found any simple way to make the conversion in blender. It would be nice to do because that what in the way for writing a usable addon for importing sIBL sets.

Hah! This part below saved my life again :yes:

You may want to complement the lightning with sun lamps, then set the sun lamp to ‘This layer only’ under lamp (beware, theres a ‘this layer only’ under shadows to) and in the lamps object tab make it active on all layers You want it to lit - But don’t make it active in the background or reflection layers, that’s what we want to prevent, that our spheres shadows the sun out!

You keep saying “lightning” when I assume you mean “lighting”.Ha Ha I searched for a lightning bolt tutorial and this thread came up. . .

Nice. Enjoyed it. Keep it up.

Hi

I wold like to give the sIBL 8k high resolution image bact HDR from the low HDR.

How can i do it?

EDIT
Nevermind, the low res HDR will work.

VERY VERY GOOD! I was always having problems with HDR and spherical images in blender.
I found BI doesn’t support LatLong for sky, and only light probe (ang), while cycles supports LatLong (not sure about ang)

I also found, that if you convert a lat long into a ang using HDRShop, there is no space that is distorted/has no data (grey area)

I found BI doesn’t support LatLong for sky, and only light probe (ang), while cycles supports LatLong (not sure about ang)
BI now supports the same equirectangular coordinates as cycles http://projects.blender.org/tracker/?func=detail&atid=127&aid=28094&group_id=9
Just get a recent build to have the option available.