How to achieve realistic TV lighting using V-Ray for SketchUp and Photoshop

The purpose of this tutorial is to explore the different techniques in visualizing T.V. screen with light effects using V-Ray for SketchUp and Photoshop. Lighting-up the T.V. screen using V-Ray for SketchUp requires specific lighting features which enable the screen to emit lights. These V-Ray lighting features includes (1) V-Ray rectangular light and (2) emissive light. During the rendering procedure, it is important to know the application and proper placement of these two V-Ray lighting features in order produce a clear rendered image of a T.V. screen that glows and lights the surrounding environment specifically in the dark room scene. As an alternative, we can use Photoshop in order to create T.V. lighting effects on screen.

For this tutorial, we will be using the following 3-D models:  (1) Flat T.V. screen, (2) 3-D people in a sitting position, (3) window and (4) chair. You can find similar items in 3DWarehouse.

First, create a simple scene using SketchUp. See the image below for reference. When done, you can proceed to rendering procedure.

Here is my SketchUp 3-D model scene. I will be using this simple scene to show you how V-ray lights work in emitting lights on T.V. screen model. Our 3-D model scene is set in a closed room with one window. The window will serves as a passage for natural lighting inside the room.

SketchUp Scene (Plan view)

Test render using V-Ray for SketchUp

METHOD #1: V-Ray Lights (Emissive light + Rectangular light)

STEP 1: Open the ‘Material Dialogue Box’, apply any color or material for the T.V. screen model. Later, we will replace this material with Emissive Light in V-Ray. The material that we use from SketchUp 'Material Dialogue box' will only serves as a reference guide in order to easily locate the material(s) in V-Ray ‘Material List’ during material editing procedure. Here, I select ‘Light blue’ color texture and apply it on T.V. screen model.

STEP 2: Open your V-Ray ‘Material Editor’, then locate the texture you applied on the T.V. screen. After that, add the ‘Emissive Map layer’ to your material.

Here is the default appearance of Emissive Light material.

Test render with Emissive Light map layer. 

STEP 3: Once you have created an Emissive Map layer, load a bitmap image on ‘Emissive color’ box. This will enable us to project the image on the T.V. screen with light effects.

STEP 4: Under the ‘Emissive color’ map layer, select the ‘Bitmap’ then load the image on the ‘File’ box.

STEP 5: Choose your desire image for your T.V. screen then click ‘Open’

Reference photo (source material): https://sports.yahoo.com/manny-pacquiao-hands-keith-thurman-his-first-loss-in-thriller-051359771.html

Result so far. 

STEP 6: As you can see, the loaded image is not properly scale. Stretch the image from the T.V. screen model. To do that, click the T.V. screen model. Take note, if your model is in a group or component, make sure to double click the model until you properly selected the texture. After that, ‘Right click’ on the image texture of the screen and then select ‘Texture’> ‘Position’.

STEP 7: Adjust the image until it fits on the T.V. screen. Here, I adjust the size of the image by stretching it along the ‘Green’ and ‘Blue’ axis.

STEP 8: Going back to ‘V-Ray Asset Editor’, adjust the intensity of your Emissive material, based on your preference.

RENDERED T.V. SCENE (INTENSITY 1.0 to 3.0)

STEP 9: Add some V-Ray ‘Rectangular Light’ to your scene. This will enable us to enhance the light intensity that will project from the T.V. screen. Place your V-Ray ‘Rectangular Light’ parallel to your T.V. screen. 

STEP 10. Go to V-Ray ‘Rectangular Light’ settings and check the ‘Invisible’. Adjust the light intensity with values around 60-90. When done, click the ‘Render’ button.

FINAL RAW RENDER RESULT (METHOD #1)

METHOD #2: Photoshop

For this method, we will be using the same model scene.

STEP 1: Open the ‘Material Dialogue Box’, apply any color or material for the T.V. screen model. Follow my V-ray settings. Here, I will be using 3 render elements which includes (1) Object ID, (2) Material ID, and (3) Total Light. When done, click the ‘Render’ button.

STEP 2: Save the rendered images including all the render elements.

STEP 3: Open all the rendered images to Photoshop. Place the ‘Total Light’ image above the RGB (Background) and set the blend mode to ‘Screen’ with 100% opacity.

STEP 4: Open the T.V. screen image in Photoshop. Adjust the size of the image using the ‘Scale tool’. To do that, go to ‘Edit’ tab> ‘Transform’> ‘Scale’ or (Ctrl+T for shortcut). Hold the ‘Shift’ key while adjusting the image in order to maintain the proportionate size of the image. 

T.V. Screen Image for Photoshop Reference Photo

STEP 5: Adjust the image using the ‘Distort tool’ by going to ‘Edit’ tab> ‘Transform’> ‘Distort’ or (hold the Ctrl key while adjusting the corner of the image.) When done, hit ‘Enter’.

STEP 6: Using the ‘Magic wand tool’, with up to 50 ‘Tolerance’, select the T.V. screen from the ‘Material ID’ or ‘Object ID’ layer. 

STEP 7: Going back to T.V. screen layer, right click on the image and click ‘Select Inverse’. Then hit ‘Delete’. This will enable us to delete the excess image from the T.V. screen. When done, use the ‘Lasso tool’ and click the image.

STEP 8: Make a copy of T.V. screen image layer and set the blend mode to ‘Screen’. 

After a long process of making a basic T.V. lighting effect, let us enhance the rendered image we made so far using Photoshop.

STEP 9: If you want a brighter scene, you can duplicate the ‘Total light’ layer or you can increase the ‘brightness’ settings. Here, I add ‘Brightness’ and set the value to 48. Place this layer under the T.V. screen image layer.

STEP 10: In order to bring a more natural bounce of light projecting from the T.V. screen, we need to apply additional ‘Brightness’ effect with ‘Drop shadow’ on the T.V. model.

STEP 11: Click ‘Add Layer’ then fill the area with white color using the ‘Paint Bucket tool’.

STEP 12: Change the scale of the ‘white color’ layer by going to ‘Edit’ tab> ‘Transform’> ‘Perspective’.

STEP 13: Select the ‘White color layer’, then apply the 'Gaussian blur' effect. To do that, go to ‘Filter’> ‘Blur’> ‘Gaussian Blur’ then press Ok. This will serves as the light ray of the T.V. screen

STEP 14: Select the ‘White color' layer and gently erase the excessive part of light rays.

FINAL RENDERED IMAGE (METHOD #2)

FINAL RENDERED IMAGE (METHOD #1 AND METHOD #2)

OTHER RENDERED TV AND COMPUTER SCREEN (MY ART WORKS)

For more in-depth tutorials and explanation with regards to V-Ray lighting and Emissive light, you can check out some articles and reading materials from these site. (See link below)

Vray for SketchUp: Emissive Material from Chaos Group

SketchUp V-ray lighting tutorial from SketchUpArtist

BRDF terms from Wikipedia

Thank you for Reading!