Corona/max render combined with sketchup linework in post, Camera Problem.

[Torsten]

Hi guys,

My workflow at our architecture is modelling, texturing and camera placement in Sketchup.We then import it into max to render with corona.
But now i also want to overlay the sketchup lines (exported as jpeg) in photoshop on top of the rendered image. The problem is that the cameras imported into max don't line out to the original scene in sketchup.
Does anyone have experience with this problem?

[phildavis17]

We have a Sketchup based workflow here, and have also had difficulty matching camera views with 3ds Max. If what you need is just the lines, you might have an easier time using a CTexmap render element with the CoronaWire map. It won't be the same as Sketchup, but it has been close enough for us in the past.

[Torsten]

Hi thanks for your reply!

Yes i tried Ctexmap but didn't find it much convenient and as nice as the different styles in Sketchup. Also my employee really likes the sketchy lines for previz works (mostly exteriors). So for these visualisations I need to drop Max/Corona and switch to Blender as this workflow works really neat. In blender the imported Sketchup Scenes are exactly the same as in sketchup.

But it would be really nice to have this method working in Corona/Max.

[pixelab]

I cannot answer your question directly, but I strongly recommend Alex Hogrefe site : https://visualizingarchitecture.com/

He has a long series of posts on 3dsmax / sketchup renderings, even if it's mostly post production and I don't know if he mixes the different renderings for 1 image.

[Noah45]

All the designers (in my world) use SU , typ. not important to exact match 'their' camera. Tried to match SU camera previously, , to no avail...
Try p-soft, illustrate, final toons, for your line overlay, then you got you max cam.

[Torsten]

Yes i am aware of the knowledge of Alex Hogfrefe. He really does a lot of great tutorials. Also that is the workflow i use too, but than at the moment i use Blender/Cycles for rendering as the cameras match exactly. Alex Hogrefe does it all inside sketchup as for what i can read on his website (vray for sketchup).
But i would love to use corona for it because of the double work by using two different kind of software. Guess it has to do with 3DsMax being the problem.

[Dream Think Lab]

A few years ago I needed to do an exact match to a Rhino camera.  I can't recall the exact workflow but I was able to get a 99-100% accurate match.  I am not sure how SketchUp cameras operate but if I recall correctly Rhino relied greatly on the aspect ratio of the frame.  Changing the aspect ratio changed the film gate / sensor size of the digital camera.   I was able to use a reasonably simple formula to calculate what the resulting sensor size was, and then plug that into Max along with the same focal length and aspect ratio.  This resulted in an exact match as long as no one changed the aspect ratio that was used.

I am not sure any of this helps you with you as I don't use SketchUp but perhaps it will lead you down the path of researching how the SketchUp camera works and how that might be translated to Max.

Please keep us updated on your progress.

[Dream Think Lab]

Yes i am aware of the knowledge of Alex Hogfrefe. He really does a lot of great tutorials. Also that is the workflow i use too, but than at the moment i use Blender/Cycles for rendering as the cameras match exactly. Alex Hogrefe does it all inside sketchup as for what i can read on his website (vray for sketchup).
But i would love to use corona for it because of the double work by using two different kind of software. Guess it has to do with 3DsMax being the problem.

Just be sure that you are not making things more difficult than they need to be.  The more difficult it is the more likely you are to a failure leading up to a deadline resulting in poor quality or missed dates.

Rely on the K.I.S.S. concept as much as possible.....   Keep It Simple Stupid.

[pixelab]

FWIW I've asked a SU veteran and here are his comments :

- If you want a special aspect ratio, he used a special utility in windows to resize his window to the desired dimension in pixels
- You can select the FOV in SU by typing "35mm" in the bottom right (usually FOV is initially displayed in degrees.
- SU field of view is based on the diagonal of the image (not sure this has an impact) and Max FOV is based on the width of the image (a 2/3 image in 36mm is actually a vertical 24mm, etc.)

This should help you in your tests.

[Torsten]

Thanks for the input! I will give it a try with adjusitng the camera's to fit the sketchup scenes, but it seems like a lot of work if you have multiple views/cameras. I quess i will stick to my method using Blender/Cycles and not make it a lot more difficult.

[Torsten]

Just an update. I succeeded using the method of pixelab. You need to check the resolution of your image in sketchup (file export 2d image) that is the ratio you need to set in 3dsmax (in render settings). Than you also need to make sure the FOV is the same. For more  control over the camera you can convert the standard camera to a physical cam (found a script online). Than you can vertical shift if needed (i found that usefull to position the composition better). I tried it and the linework from sketchup can be overlayed on top of the rendered image. It is a bit of a work around but it seems to work.