In this example we will explain how to make Projection Light. We prepared two sample scenes for you to download. You will be working on the "Default" from these scenes. "Finished" is a scene ready for rendering. If you want, you can open it.
Download the scene from here
1- First open the default scene. Create an "Area Light" from the LV. Position this Area Light on the front of the projector machine. Set the rotation so that the "Z" axis faces outward.
2- Now select Light Tag from object manager. Load any image you want to project to the distribution channel (remember to use Octane Image texture node). When you first load the image, you will not get the result you want because of the default settings, so you will have to do some setups. First, turn off "surface brightness," which means that the power will stay the same regardless of whether you enlarge or shrink the light object, then shrink your light object very much with the scale tool until you see the picture clearly. Make the light power setting between 600-800 for now.
3- As you can see, even after you have scaled the light and see the picture clearly, we are still far from the correct result because the projection and transform settings of the image has not proper setup. We have to solve that.
3- Now you need to set the "Projection" and "Transform" settings for the image you have loaded. Let's do the Projection settings first. Click the Projection button and change the settings as you see in the picture below.
4- After making the projection setting, you will see a result as you see in the picture below. Here the picture looks in reverse. You also need to "Transform" the picture to make it smaller.
4- Now click the Transform button and first select Transform Type as "2D Transformation". Then adjust the image's transform settings so that it fits exactly on the screen. What you need to do in this section is to play with all three transform axes. Finally, select "Border Mode" as black color from the Image texture settings.
5- After this setup, your Light Projection should now be correct as you can see in the picture below.
5- You can add visual appeal to render by giving the "volume effect" to the projection light. For this, you can apply this method from the previous section "Making Volume Lights".