[flow_default] Transcription: 01_image-based_lighting_03.json

transcriptions/01_image-based_lighting_03.json

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+{
+  "audio_file": "01_image-based_lighting_03.wav",
+  "text": "Fortunately, extending the dynamic range of a regular 8-bit image is quite trivial in Blender. Very easy indeed. So we need to do something with the strength of our emission, but do it in a kind of interesting way, prioritizing some parts. I'll make some room for the nodes after the texture, I think. And now we can go Shift A for the Add menu and add the Value node. Let's copy out the strength from the emission to this new node. Ctrl C while hovering over the value then Ctrl B to paste. No clicks involved. Right, now we can go Shift A once again. One more value node for the bright parts this time. Ctrl C, Ctrl V just for fun. Then this number, the second number will represent the multiplier for the bright parts. It should be, let's put it like that, it should be many times stronger. Like 11, why 11? 11 is like 300 times bigger than our measly 0.04, so it should give us enough power. These two values should go into the RGB mixer, A and B sockets respectively. Once again, these values represent the base and the extended range, if that makes sense. We need one more component to make it work though. We need a mask to define where to show these brighter values. I think a simple color ramp will suffice for that. Shift A, add in a color ramp. Move in some nodes around. Don't pay attention. A usual business. What we need to do though is take the color output of the original texture and pass it through the color ramp. So here it goes. And then we can connect it to the mix factor like that. The connection is a bit cluttered. I think I'll just shift right click and drag across the line to add a point there then tidy it up like that. The results of the mixed node should go into the strength of our emission. And voila, the neon lights and other such stuff within the image got a considerable boost. It's the second value that got applied to them, the almighty 11. Now we can tweak the ramp to fine tune what elements should receive this extended range. We can define them really easily just by moving the black flag. By the way, with Ctrl Shift the contents of the color ramp could be previewed to just see the mask. Basically it's a black and white mask that controls the extra brightness. Crunching the left flag like that would limit the effect to really just a few spots that will end up really shiny. Moving the right flag would affect the brighter parts. You can reduce the contrast by adjusting these flags I guess. Something like that. Actually I want to preview how the full material looks so I'll Ctrl Shift click the emission shader, the final one. Well now some of the signs got fairly hot in comparison to how it looked before. Again we can control the exact amount of heat within that second value. I don't have a precise science there for you. I'm just going to pretty much eyeball it so it looks realistic to me. Imagine the bright neon lights at night. That's kind of ratio. So maybe something like, I don't know, something like 2 for the HDR factor and well, something like 0.08 perhaps for the base. That ratio could be pretty subjective I guess and it could depend on the genre, on your creative goals after all. How contrasty do you want it to look? And then the mask that takes everything that is brighter than the night sky, let's say, and boosts it. Especially the signs and stuff like that. Maybe we can crank up the HDR factor furthermore. For or even more. It's so cool to have these parts reflected in the ground and generally starting to illuminate the scene with their light. It's interesting that these areas are rather small, so they should cast the hard shadows. Like if there was a cube there or something, you would see harder shadows from these hotter parts of the environment affected by our edge-erisation process. That is awesome, I think, that it illuminates the scene in such way and the smaller bright parts generate harder shadows. I'm gonna hit X for delete, zero on the numpad to go back to the camera view. The base and the extended values can be adjusted based on the source image and need to be adjusted based on the source image. By the way, remember we have sampled the pixel values in Render. Let's do it again. And compare. It's rendering pretty fast nowadays. Let's control right click on the yellow pixels. And yeah, see the numbers. Three in red, 2.39 in green and almost no blue since it's yellow. Now we are talking. These are fairly hot yellow pixels, each one being a light source basically, pushing these values into the senors photons. So what we did is this. We took the original photo used as an image-based light source and we extended its dynamic range to make it a better, more realistic light source. That is good. Another way to check the range is to reduce the exposure in the color management that can be found in the render settings. Look at that. We bring the exposure down, but these extended values still remain bright. That speaks of their range. That makes it a better light source generally, makes it more realistic, because the difference in levels between the night sky and the neon signs should be a few orders of magnitude. We have nailed that by our process of HDRization of the source, JPEG or whatever image we use for our image-based light source. There's one thing left that I would still like to do with our edge-derification nodes. Allow me to create more space for the shader editor so we could see the node set of better. So I would love to be able to adjust the color and the strength of our image-based light material. That would come in handy later on once we group these nodes. For now, I'll first click and drag to select these nodes like that. Oops, let me do it again. So click and drag over these nodes like that. And then we need to right click the empty space and make group of these nodes or control G if you prefer shortcuts. Tab teleports you into that group and tab gets you out of it or this button if you like buttons more. So we have grouped the nodes doing the hdrification and got two outputs stretching away out of it. So far it's a mess. The lines are crossed and it's not clear what's even going on here. Let's tidy it up. First I'll call it HDRI, then gonna select it and press TUB to expand the group. And remember that TUB is your ticket out of any group as well. So yeah, forget it and you will be stuck there forever in a spaghetti monster hell. As far as the input goes, we don't need to touch it. The output needs to be set up. I'll select it, press N to open the right tool shelf with the settings. Then we need to go to the group settings over here. And here we have our outputs. I'll hit the down arrow to move this output down so color is our first one now. And this is gonna be our strength. So we got color and strength. The strength being our shenanigans with HR values and the color being the color output of our photo or image texture. That should tidy things up. Let's press this button to get out of the group safely, then end to close the tool shelf. And that is much cleaner looking group now for sure. That is really awesome. Now we can apply some basic color gradient on top of it. I'll go color, hue saturation value, favorably standard stuff to adjust how colorful you want these colors to be. Or shift the hue a bit, although this is rarely how I do it, as it's much better to change the hue in a different way that I'll show later in the video. But we can do it here as well. Just don't ask too much from this node. It's a fairly basic stuff. That's it for the color for now. We'll do more later. What other things can we adjust now? Like what other nodes can be add after the group? The strength needs its own local multiplier by the math node that we have to drop over this line to automatically plug it like that. And it has to be set to multiply. So it turns into a basic multiplier. What we have just done is we gave this object a few extra controls of a color and level if needed. That will come in handy in just a moment because we'll keep adding a few more screens around our scene. These screens will share the HGRI group that we have just created, but will have their own local controls that we have just added. And these controls will be unique per material or per screen. If it sounds strange or something, it will all click in a moment. I promise.",
+  "language": "en",
+  "confidence": null,
+  "duration": 771.33
+}