Blender Physically Based Shading: Theory
I wanted to build this roof
But had to go looking for geometry nodes to make the tiles align sensibly. I knew I had it in this fish statue file. I think @higgsas made them. I got sidetracked playing with the fish again. I still don’t actually understand the nodes so I can’t apply them to the roof yet :(.
To get the nodes to work better on the fish involved quad remesh addon, smooth modifier, smooth corrective modifier, alt+s shrink fatten on edge loops and individual verts, scultp mode: smooth tool, slide relax tool, inflate tool.
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export to blend addon
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I used an armature to straighten out the fish and now the scales at the very bottom are going crazy again.
This screenshot is with laplacian smooth modifier, it’s doing an amazing job everywhere except for the bottom:
Chaing this align euler node makes it not as horrible but not quite right, a lot of the tilted overlap of the scale is lost in the front smaller faces now
But this now looks much worse on the original fish body
starting over
On a cylinder with a rounded end it looks pretty good.
But if I rotate the cylinder and apply rotation there is like a direction bias to either up or down.
Rotating back to vertical and applying fixes it. I don’t understand what the nodes are doing at all so I can’t find where this directional bias is 
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Good job on the fish; the final render looks great!
I had a look at the blend file from your previous post. I am by no means a geo-nodes expert, but it looks like if a Rotate Euler node is placed as below, the scale flow rotation can be controlled.
Also, I suspect the bottom scale craziness could be related to the nodes labeled “Creating Flow Directional Vector.” Disconnecting those nodes has no impact on the result, I think due to the red undefined node groups.
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lighting + volumes is kicking my ass
instead of underwater it should be like water is receding from the scene. should be easier to light then.
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\\SILVERHAWK\exposure testing.blend
Using Physically Correct Brightness in Cycles
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I suck at math.
I never got into real camera because of the amount of albeit simple math you need to do every few seconds.
EXPOSURE
What does a stop in photography mean?
A stop is a doubling or halving of the amount of light let in when taking a photo. For example, if you hear a photographer say he’s going to increase his exposure by 1 stop, he simply means he’s going to capture twice as much light as on the previous shot.
If exposure is doubling the amount the amount of light
at every higher whole number, then a light source with
strength = 1 and exposure = 10
should look the same as
exposure = 0 and strength = ???
exposure 0 is whatever the light strength (LS) current is.
It's currently LS = 1.
exposure 1 is LS 1 * 2 = 2
exposure 2 is LS 1 * 2 * 2 = 4
exposure 3 is LS 1 * 2 * 2 * 2 = 8
exposure 4 is LS 1 * 2 * 2 * 2 * 2 = 16
exposure 5 is LS 1 * 2 * 2 * 2 * 2 * 2 = 32
exposure 6 is LS 1 * 2 * 2 * 2 * 2 * 2 * 2 = 64
exposure 7 is LS 1 * 2 * 2 * 2 * 2 * 2 * 2 * 2 = 128
exposure 8 is LS 1 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 = 256
exposure 9 is LS 1 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 = 512
exposure 10 is LS 1 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 = 1024
1 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 = 1024
So a light strength of 1024 at exposure 0 should look the same as a light strength of 1 at exposure 10.
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dammit, got a light leak in the left corner
\Downloads\blender demo files\classroom\classroom\3.6α classroom.blend
Getting that bevel in the corner of room walls has always sort of annoyed me. Simple solution is to have a cube with a bevel modifier but then you use booleans for a window and for some reason the bevel size changes, or you want to only have 3 walls for an orthograpic shot so now you’ve got to delete a face on the cube, etc.
This scene makes the corner bevels very simply:
But the edges need to overlap to prevent the light leak.
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Testing the “IO Export to Blend” addon by converting everything in the Barber Shop demo scene into assets.
It’s not going well. Every export is a 70mb file because it’s not successfully deleting everything from the original file except for the selected items. For example I exported first two hanging towels and back linked them. Then i exported the umbrella holder. If I look in the exported umbrella holder’s orphan data there is every armature, object, material, and collection from the original file. There is also the link data to the 2 towel files. All that has to be removed manually to bring the umbrella holder file down to 10mb 3mb 2.5mb 1.5mb from the original 70mb.
Never forget that deleting things in Blender is always a 5 step process. Delete it, then find it in one of the sub modes of the outliner and right-click delete it again, then File → Cleanup → Recursive Unused Datablocks, then do that last step again, then save the file. Then open the file and do Cleanup again and save and close the file.
I’ve given up on using the addon. Will test if it’s better to open 2 instances of blender and copy/paste assets out of the main scene file. It’s technically slower than the addon since the addon had that backlink feature to replace the original objects with a collection. But because backlinking that way created an asset that was positioned relative to the original scene’s world origin instead of a manually setup asset that could be immediately used as expected in any scene, it doesn’t really save me time.
It doesn’t make asset thumbnails.
adding asset thumbnails increases the file size a little more than I hoped it would.
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barber shop demo scene
These are vertex colors which are then mixed with pointiness edge mask and a wood texture and a grunge texture.
The lamp shade is really nice. I wish I understood the material nodes.
Each lamp has an armature and one of the bones in it has custom properties that can manipulate the light. I wish such things were straight forward and did not involve drivers and custom properties. Those things seem so brittle, especially when you duplicate an object.
The building itself has a rig with custom bone objects and custom properties and drivers for hiding each wall of the building from viewport or render. I can’t get it to work though.
My computer isn’t good enough to stay in cycles viewport all the time. Eevee is also slow. Unfortunately solid view doesn’t do a good job of showing all the things it could show all at once. The ability to custom tailor a material just for solid view would be of great benefit.
Textures are not shown if the image node is not set to flat or if the object lacks uvs.
Vertex colors are only shown if Attribute option is chosen and then they are the only thing being shown.
Random colors are very useful but they ignore alpha set in material or object color so you can no longer see through glass.
Some glass materials use a roughness map and when in Texture mode you always get the opaque roughness map.
Some transparent materials use an image texture for both the color and the alpha instead of having an alpha channel.
Textures with alpha channels always show with their alpha channels applied and very often I don’t want that:
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