11 Replies Latest reply on Oct 11, 2012 12:45 PM by conroy

    Illumination in 3D not reflecting as expected

    Andymc7 Level 1

      Hey everyone,

       

      Well the pest is back with another 3D in CS6 question... I'm attempting to use Illumination on my office ceiling here to simulate light reflecting off a wood floor. As you can see, the reflections don't show up very well. Does anyone have a suggestion on how to increase the intensity of the reflected ceiling lighting in this digital room?

       

      Thanks in advance,

       

      Andy

       

      office_screen.jpg

        • 1. Re: Illumination in 3D not reflecting as expected
          conroy Level 5

          It will help if you post a photograph (or link to one) which displays the exact effect that you want to simulate.

          • 2. Re: Illumination in 3D not reflecting as expected
            Andymc7 Level 1

            Similar to this, but of course the reflections more in the shape of the actual lights, or rectangular

            wood_floor.jpg

            • 3. Re: Illumination in 3D not reflecting as expected
              Andymc7 Level 1

              I'll also note that for anyone that's familiar with Maya or Max, this would be achieved by using global illumination with the mental ray renderer. At least in my version of Maya. So, you may ask, why not just do it in Maya? well, as usual, I'm trying to blend 2D and 3D elements, so PS CS6 would work great for that, if I could get my flooring how I want it...

              • 4. Re: Illumination in 3D not reflecting as expected
                conroy Level 5

                I recommend you do a separate rendering pass of reflected ceiling lights and composite that with the main rendering. That'll give you limitless control over the final result.

                • 5. Re: Illumination in 3D not reflecting as expected
                  Andymc7 Level 1

                  Hmm,... ok, so are you suggesting I do something like dupe the whole 3D layer, remove the floor's texture, render again, rasterize, desaturate then experiment with contrast and blend modes (hard light/overlay maybe)?

                  • 6. Re: Illumination in 3D not reflecting as expected
                    Andymc7 Level 1

                    Well, it seems now no matter what I try, I can't get enough reflection in the floor from those ceiling lights at all. I've tried multiple material settings and nothing seems to work. At this point, I would love to see a simple reflection of the ceiling in the floor. Ideas??

                    • 7. Re: Illumination in 3D not reflecting as expected
                      Noel Carboni Level 8

                      Are you sure your angles are right so that you'd be able to see such reflections?  A light has to be kind of far off before it will reflect on the floor.  What happens if you raise the camera angle and have it look more downward?

                       

                      Also, try working in 32 bits/channel mode - the 32 bit environment handles calculations beyond white, so lights can be brighter than white walls, for example.

                       

                      ReflectionInFloor.jpg

                       

                      -Noel

                      1 person found this helpful
                      • 8. Re: Illumination in 3D not reflecting as expected
                        Noel Carboni Level 8

                        Oh, and one other thing...  Try shining an infinite light on the ceiling.  Without that the texture seems to just look flat.

                         

                        NoLight.jpg

                         

                        -Noel

                        1 person found this helpful
                        • 9. Re: Illumination in 3D not reflecting as expected
                          conroy Level 5

                          Render in 32-bit mode. Make the lights' material self-illuminating as in real life. If you've modelled them separately from the ceiling then you could assign a high-intensity illumination colour. If they are just "painted" on the ceiling then use an illumination texture as in the example below. Note that I set the scene to have hidden backfaces, which is why the ceiling is not rendered in the view from above it.

                           

                           

                          Rendered reflections of ceiling lights

                          Screen shot 2012-10-11 at 15.24.49.png

                           

                          Ceiling selected

                          Screen shot 2012-10-11 at 15.28.32.png

                           

                          Ceiling material

                          Screen shot 2012-10-11 at 15.29.34.png

                           

                          Ceiling material illumination texture

                          Screen shot 2012-10-11 at 15.33.57.png

                           

                          Floor material

                          Screen shot 2012-10-11 at 15.30.27.png

                          • 10. Re: Illumination in 3D not reflecting as expected
                            Andymc7 Level 1

                            Thanks so much for these replies!

                             

                            First off, I must have had a misunderstanding about specular color. I thought it controlled the amount of reflected light in a material. But on your "floor" conroy I see the specular is turned all the way down, with only a 15% reflection value. I was turning my reflectivity up high (80-90%) and also amping up the specular, and still not getting the results I wanted. Care to put in dummy's terms for me what specular is?

                             

                            Also, could switching to 32 bit really make that much of a difference? wouldn't I still be able to see some sort of reflection in my floor?

                             

                            At any rate, I will try a test run using the tips you guys gave.

                             

                            Thanks again!

                            • 11. Re: Illumination in 3D not reflecting as expected
                              conroy Level 5

                              The Specular and Shine controls affect the highlight on a surface that results from non-physical illuminants - Point Light, Spot Light and Infinite Light. My example used none of these lights, so it wouldn't matter what the Specular and Shine were set to in the materials.

                               

                              32-bit floating-point per channel mode deals with colour components which are not constrained to the 0-1 normalized range of integer 8-bit and 16-bit per channel modes. This allows you to simulate the dynamic range of real-world light, giving more realistic results than are possible with the integer modes.

                               

                              Take your ceiling-with-lights texture, for example. In 8-bit or 16-bit modes, you might paint the ceiling with 75% white and the lights with 100% white (ignoring colour for simplicity). In the real world, the lights would be many times brighter than the ceiling. 32-bit mode allows you to texture the lights many times brighter than the ceiling.