HDRI for lighting but not background

Support Lighting and Rendering
1

I want to use an HDRI for lighting but not for the background, and I don’t want a transparent background either. Some time ago I found a solution to this, but can’t get it to work now so there must be some setting I’ve forgotten.

Solution was to enclose scene in a large sphere, reverse the normals on the sphere so the outside was supposedly invisible and light passed through from the HDRI, but on the inside you saw the surface of the sphere. It did work when I first found it, but can’t get it to work now. I enabled backface culling but no improvement, so there must be some other setting I need to set. I’m using cycles.

2

You can separate objects from the background via “is Camera Ray”.
Basically this setup here:

image
image1198×817 98.1 KB

3

Thanks, but this is giving me some strange lighting - this is just a plain green cube.

green_cube
green_cube1920×1080 279 KB

4

I don’t know exactly if you are interested in this but it might give you an idea, essentially here I I want to use the technique of making “Invisible Light Emitter”. However I don’t want to control the transparency with “Is Camera Ray” (to make it invisible to camera), I want to use the “Backfacing” ray in order to delete the front facing pixels.

2020-01-14 10_16_32-Blender C__Users_cos_Documents_hdr_transparent_surface.blend
2020-01-14 10_16_32-Blender C__Users_cos_Documents_hdr_transparent_surface.blend821×699 309 KB

5

The orange texture node is an “Environment Texture”. In there goes a equirectangular Hdri. i.e.: https://hdrihaven.com/hdris/

Also try to raise the viewport sampling count in the render settings on the right.
It would also help to know how new you are to blender… :slight_smile:

6

Thanks, yes I was using the wrong type of texture node. I use the EasyHDRI plugin for my HDRIs because it’s easy to change which image to use and also to adjust rotation, strength etc. Your node setup does work with that so it looks like a good way to go.

I’ve been using Blender for modelling for about 10 years but until recently have done most of my scene setup and rendering in Vue. It’s on ly in the last few months I’ve been using Blender and Cycles almost exclusively. Still a few gaps in my knowledge!