HDRI Horizon Layering Kitbash

Problem: I needed a specific horizon, and adding large-scale hills/mountains/trees to an already existing scene was too much for my system.

Solution: Layer a .png rendered with the spherical lens over an .hdr in Photoshop.

Needed: DAZ Studio, an existing HDRI product, a model/scatter for the horizon, and Photoshop (or a photo editor that can read/save .hdr files).

Used in this example:  https://www.daz3d.com/ibl-skies-clear-skies and https://www.daz3d.com/dry-mud-desert

How to: Load both products above into Studio. Under Render Settings, Environment, turn the dome and ground off, and under General, set the size to Width = 8192, Height = 4096, set the path to where you want to save, name your file, and choose .png from the dropdown. Load a new camera and position at Translate X = 0, Y= 30, Z = 0, and Rotate X = 0, Y = -90, Z = 0. Set the Lens to Spherical. Render and save. Under Render Settings, Environment, click on the thumbnail under Environment Map, choose Browse, double-click in the address bar to select it, right-click, and choose copy. In Photoshop, click Open, File, and paste the copied address. Choose the HDRI you used and double-click to open its .hdr file. Navigate to your saved render and open it, too. In the tab with your render, click Image, Image Size, and change the resolution to 72 and the Height to 8192 with constrain proportions locked so the width changes, too. Click Image, Mode, and change it to 32 bits. Drag the layer to the tab with the HDRI in it and hold down shift as you drop it over that file. Choose File, Save As, and save in a different folder as an .hdr with a different name. Back in Studio, click on the environment map thumbnail again and browse to the saved file to load. Turn your dome and ground back on.

That’s it! 

https://youtu.be/4JhdpUAa_F8

Notes: 
I deleted the “dust haze” and “far haze” from Dry Mud Desert before rendering.
 
In Photoshop, check to make sure the grey default horizon isn’t visible behind your horizon layer. If it is, nudge the layer up until the grey is covered - this will mess up the HDRI ground in the final version, but that should only matter if you don’t intend to use a ground plane in your scene.

Add blur Filter, Blur, Gaussian Blur to your horizon layer if you want a depth of field effect.

Be aware that although this worked for me with these products, some HDRIs use a different file format.

If Photoshop doesn’t want to save your .hdr file, try first saving as a .psd file, and then try again.

Hope this was helpful.