I posted this mixed-media image in the gallery forum and some people asked how it was done. I am happy to share my photoshop techniques below:
1. The basic idea to combine the rendered image from Podium with a hidden line render of the same scene from Sketchup. Here are the source images:
This image was exported from SU - Hidden Line:
This image was rendered in Podium:
I put the Podium image on the bottom layer:
I put the Hidden Line on top of the colored one and turn on "multiply". The two images were not originally the same size. I had to scale up the Podium one and move it into position exactly to match the hidden line.
2. I added the outside trees and sky "outside the window" using a layer mask. When doing any of the below tasks, use the layer with the Hidden Line image to do all your magic wand selecting - it makes picking the area much faster and easier:
3. To get the sunlight coming in the window, save a hidden line with shadows turned on in SU (everything will be grey except the sunlight shining into the room):
Use magic wand to select the white areas, open an new layer, fill it with light grey (delete the open glass areas first) and put that on top of the color image using "vivid light". Podium could have done the sunlight but in this case it makes the rest of the room too dark, so I made the windows opaque LEMs for nicer lighting in the room and faked the sunlight afterwards:
4. Ceilings always come out too dark - that may be the reality but clients don't like that, so apply an HSL (hue/saturation/lightness) or Levels filter to it to lighten it:
5. I also adjusted certain colors using HSL filters - for example, the whiteboard under the TV was originally the same beige color as the wall around it (even though in the SU model both were white - probably the color of the floor was affecting them). I had to desaturate that rectangle and lighten it to make it look like a whiteboard:
You can also see i adjusted the color of the daybed, the curtain, the wall covering and the painting. HSL filters are great because if our interior designers want any color i can change it using HSL adjustment. Unfortunately the wall still has its original orange reflection - nothing can be done about that.
6. The wall sconce was an LEM but I added the light shining up and down using photoshop. Magic wand the shape to be lit, and use a "White to Transparent" gradient in both directions. Be gentle, and work on a separate layer so if it looks too strong you can turn down the opacity. I erased (with 50% opacity) a bit to soften the edges of the light.
7. Do everything on a separate layer or use a filter - safer, in case later you change your mind you can turn it off.
8. The sunshade is a grey shape with opacity.
9. And of course, remove any fairy lights and blotches (Clone tool is useful).
10. Add a Level filter to the whole thing to make it lighter - clients don't want to see a dark dingy room.
I actually added two Levels filters... you shouldn't have to do that. It just happened to look better that way.
And that's all! This technique is what i have been using for client presentations ever since SU came out - except before Podium i had to tediously export the model to VIZ, add lights, and render it for hours. Now, it's a piece of cake! =)