reflection distortion on glass buildings?

reflection distortion on glass buildings?

timmport
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Message 1 of 6

reflection distortion on glass buildings?

timmport
Contributor
Contributor

I have a lot of experience modeling in Maya but not so much on shading/rendering side. I am working on a series of images that will include contemporary high-rise buildings with highly reflective windows. I am particularly interested in how the reflections are distorted by each window. I have attached reference images that I will be working from which should give you a sense of what I am talking about. In my source images, you can see how each individual window warps the reflection in a unique way. I am wondering if anyone can point me to information for how to approach this? As far as I can figure, there are two basic ways to do this. 1) find a shader that will warp the reflection differently for each pane of glass on the buildings. 2) do a render pass just for the windows and composite in a sky image. For the first approach, this seems like it may be very processor intensive and put a lot of extra geometry (i.e. extra work) into the scene to create the reflected image. For the second option, I am not sure how I would get the comped reflection to warp differently for each individual windowpane. I am expecting to use Arnold for this but can go with something else if you it makes sense.reflection_building.jpgIMG_20180704_155510.jpg20gfrma.jpg

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Message 2 of 6

mspeer
Consultant
Consultant

Hi!

 

Reflection is based on Normals, so a simple normal map should do it.

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Message 3 of 6

timmport
Contributor
Contributor

I have been playing around with normals to see what I could come up with but so I am not seeing that it is changing the angle of reflection or distorting the the image that is reflected. As far as I can tell normal maps just add texture. Please let me know if I am missing something.

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Message 4 of 6

mspeer
Consultant
Consultant

Hi!

Changing normals manual or by texture (bump or normal bump) affects reflection, for sure.

See image below:

 

sphere default -- sphere (normals modified at mesh) -- sphere (bump map)

 

refl_bump.gif

 

 

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Message 5 of 6

damaggio
Mentor
Mentor

Just make a 16 bit bump map and apply to the windows, this is a very simple effect now that your have your UVs set up.

Play with the UV repeats and adjust the bump intensity to your liking and follow those  tips on your CGtalk thread, they were well explained.

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Message 6 of 6

timmport
Contributor
Contributor

Thanks guys. Your suggestions worked. I just need to fine tune it.success.jpeg

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