Photorealistic HDR Setup In Blender

Hey everyone,

Just wanted to drop a quick news on my latest tutorial submitted at chocofur. It’s about creating a quick but realistic HDR illumination setup for Blender and Cycles. I’m also covering the topic of adjusting the HDR image for 3D CG use, as well as share one, free 12000 x 8000 px HDR map for you to use in any commercial / hobbyist project.

Hope you’ll find it useful in your daily work!

Free HDR:

cool trick, thanks :slight_smile:

Thank’s @lechu!

This will come very handy :slight_smile:
One of probably many ways of adjusting brightness of a HDRI using Cycles only. It basically ramps up at a given setpoint, and allows clipping. Preview lets you see unaffected (outer), affected (middle), and clipped (inner) values. Adjust preview first to “isolate the sun”, then turn off preview and adjust until sun casts a decent shadow and provide a good visible terminator for diffuse shading. Although it’s only done by “eyeballing”, it works surprisingly well as far as “visible sun based HDRIs” goes.

@CarlG, nice your node, I like it, thx :wink:

Normal node

CarlG node

@CarlG: it’s not only about adjusting brightness and shadows. If Blender allowed texture keying on Cycles shading level then I think lot of work could be handled in Blender itself. But still it’s more than just general brightness tweaking.

I just presented a method that works well for me. I don’t have access to Photoshop, nor the time to tweak all my outdoor sunny HDR’s using a paint prog. Some time ago I noticed that the sun disc and corona tends to be the only thing in such images that does not cover the full tonal range (direct reflections excluded). It’s probably not perfect, but it does give me instant sun fix with minimal efforts. Your method actually fixing the tonal range may probably reduce noise generation, if as I suspect MIS samples the HDR used rather than the shader output. Also the method I showed is unsuitable for a sun partly covered by clouds where clouds are also clipped.

Again, it’s a Cycles only alternative for those who can’t spend time tweaking or can’t afford expensive software :slight_smile:

What’s the advantage over this simple and well known method to increase the strength of the sunpoint ?

Thanks for the tutorial!

@tompov: the difference is you’re only multiplying the input file with clamped EV values (which is the case I was referring to in my tutorial). It will brighten the sun and all bright spots, but won’t add any color / light information to HDR map areas that should be real light emitters. For instance this method won’t work for the cloudy sky HDR image as it will brighten up the entire, grey sky instead adding extra EV levels to the sun area covered with clouds. I simply think adjusting the map in 2D is better since it’s quick and works regardless to the software.

@CarlG: I think Gimp also allows a pretty decent HDR editing after empowering it with certain plugins.

Thanks @lechu! The tutorial was really helpful!