Tone-mapping is generally necessary in architectural interiors. Learn how to render and tone-map it to adjust brightness and contrast.
- [Instructor] In this video we're going to render an interior space and tone map the results. Before we get into that, let's examine this model. It comes with a number of scenes already set up. The model also has all of the materials already assigned with Twilight templates. There are a few materials which use the Deep editor, which is the subject of a later video. In Environment, we have the physical sky with all of the default parameters.
I'm going to zoom out and reveal that this is just a single room. And as I orbit around, observe that we're able to see through the walls and see through the ceiling. And yet, those surfaces appear when we look at them from the other side. I did this by taking advantage of the fact that SketchUp allows you to have two different materials on each surface. I will go Select the wall object, double click to open it for editing, and then click on one of the surfaces.
Go to Entity Info and here you can see that the front of the wall has a paint material, and the back has a transparent material. It has zero percent opacity. So we can see right through it. This is a useful trick that allows you to work on an interior space and look right into the room. Otherwise, this would just be a solid box and we wouldn't be able to see what's inside of it. That said, let's go into Scene 1 and do a test rendering.
Choose medium as the preset and set the size to be 800x450 and uncheck Fit to view proportions. Then render. Now I'm expecting this rendering to be quite dark because there's only one light source, namely the environment, and it's coming in through the window. This is an artifact of what the buffer had in it previously, which was a thumbnail image of the environment.
But now we're starting to see the rendering take shape, and it is way too dark. So your first impulse might be, okay, it's took dark, I'm going to go over to the environment and increase the brightness of the physical sky. But don't do that. The physical sky is set up to use a brightness of one. There's no reason to ever change this. Instead, what you do is you change the post-processing on the rendering, and this works because the information that is actually rendered is high dynamic range imagery.
That means there's more information in the rendering than can actually be displayed here on screen. And we can alter the way that that data is displayed through post-processing tone mapping. So open this up, and here we have, under Image, we have ToneMap. Let's choose Simple, and increase the exposure. Let's say it's two, how about five? It starts to brighten up considerably.
So this information is already rendered. It's our task to ToneMap that information to make it display in a aesthetically pleasing way. So by boosting the exposure up five stops, it's starting to look a lot better. You can also change the gamma. So exposure is kind of a global control, whereas gamma affects the mid-tones. And gamma is set at one by default. So if you want to brighten the mid-tones, you're going to increase gamma slightly.
Say it's 1.2, that brightens the mid-tones up too much, really, for my liking. Let's say it's 1.1. This has a different effect than globally increasing the exposure which affects shadows, mid-tones and highlights all together. But this is just the simple method of tone mapping. You can choose the linear method, and that gives you control in the shadows and the highlights.
So if I want the darks to be brighter, I'll increase this value here; and if I want the lights to be brighter, I'll increase this value; Or if I want the lights to be darker, I'll make this value less than one. So you can experiment with the numbers and quickly tone map your rendering without having to adjust the light brightnesses and re-render each time.
- Cleaning up geometry and materials
- Simulating sunlight and shadow
- Specifying environmental conditions
- Customizing materials
- Rendering interiors
- Creating artificial light sources
- Narrowing focus with depth of field
- Using the Twilight Deep Material Editor
- Rendering animation frames
- Creating video from rendered frames