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View Full Version : Advice wanted from rendering gurus



PeterJ
2004-06-29, 11:52 AM
Lezangem

I don't really do much rendering work, other than to sometimes convey an idea, or satisfy my own curiosity. On a current project I want to be able to produce a small number of quality images, above and beyond the kind of thing I normally produce.

I attach 3 images for you to take a look at and perhaps you can tell me the following, why do the materials look a little flat, why does the nighjt shot look so un-natural compared to some that are posted here and what is the best way to do the 'drop-in' shot, apart of course from starting with a better positioned photo. I have photoshop and can use it, if that is the first line you wheel out but I just want to see if there is an alternate response.

Thanks for any comments you can give.

fernando
2004-06-29, 12:06 PM
my "humble" contribution..
#1 i prefer to use real materials to the images of great detail, instead of native material's from acurrender

#2 to get a good merginging between a real photo and a revita image, or use photoshop to merge it
or get a few trys rendering with the photo as background, using view with the most possible angle u can get from the real photo..(many tries..)

#3 night...that's a mistery i leave to the poet's.....ehehehe

fernando
2004-06-29, 12:12 PM
3 examples of my last topic

SCShell
2004-06-30, 02:34 PM
Hi there,

I like night renderings! I have played with these for a while and have found that there are a couple of quick things you can do to get really nice looking renderings. (This method assumes that you are already happy with your day time ones.)

Take a final daytime rendering that has all of your lighting in the model, and modify it for your night view:

Take the existing scene, and add/edit a new one. Adjust your environment so that the sun is located just below the horizon line after sunset in your sun settings. (This can be played with to get a nice "sunset" view which still as some natural light along with your architectural lighting.) You can either drag the sun in the little diagram, or change the time to be after sunset depending on your season/area settings. By doing this, it will still provide some ambient light for your clouds. Set the color of the sky to black.
Make sure to leave your clouds in. This gives the rendering a very "real" look since you do see clouds at night. (In the city that is!)

Once you have changed those, simply render it leaving the lights on. In my office projects, I turn off some of the office's lights in a random pattern, much like the real world. Within the environment settings, you can actually turn on and off every individual light fixture within your model if you placed them there to begin with. It takes a while, but it is worth it sometimes. (Revit thinks it is still a daytime rendering and will ask you, " do you really want your lights on?...it may mess things up...or something like that" )

I tend to add exterior spot lights in dark areas where needed, like uplighting trees etc. Revit City had a good one and I think RUGI had one too. (A directional round head on a stem mount, kinda mushroom looking fixture with a 150 or 300 watt lamp.) If I don't want to see the fixture, I place it outside the cropped view or hide it behind something.

Good luck!
These take time to get "right". But, what is "right" depends on your objetive. It is all subjective; however, I get nice feedback and comments from clients and they help me with the lighting design.
Steve Shell

Kroke
2004-06-30, 02:37 PM
I think a lot of it has to do with (yes you said it), your materials.
Also the lighting factor.

But you also need to render at a much higher resolution...try it, you'll get rid of a LOT of that ugly grainyness.

Play with your glass / siding textures, you'll see improvments.

David Conant
2004-06-30, 04:03 PM
Some other aspects for helping rendered images sit well in context photos:
- Use depth layering so that some things in the context photo sit in front of parts of the rendered image.
- At the intersection of the rendered element and the context, try to avoid a clean seperation line. Bring a little grass up on the foundation, allow a bit of the existing building to cover the end of the new, let a tree interfere with the edge between new building and existing sky.
- Simulate some light and shadow effects between the existing and new.

An alternative is to get out of the photo real black hole and be more expressive.
- Use use photshop filters on both new and existing to give them a non photo appearance, try the pen filter. This will supress many of the differences in resolution and color.
- Make either the existing or new discernably different in character. Try using a watercolor filter on the new image before combining it with the context.
- Transform the existing to greyscale with the new in color, or vice versa.
- Dirty up the whole image by underlaying an abstract texture very transparently.

PeterJ
2004-06-30, 04:44 PM
Thanks for these comments. I will spend some time working on them.

The material issues are probably the first to address, then I'll look at photoshop and how best to to do the drop-in.

Roger Evans
2004-07-05, 11:57 PM
Pete one of the quickest solutions if you are pushed for time is just do grey scale with what you've got ~ & then maybe just darken image & crop out in your paint program. Higher res & play with materials if you have more time. All the advice given is very relevant Dave Conant's advice is especially superb.

Personally I like images combining a mix of realism with off the wall abstract ~ Plans as well as Images. Any image can be scanned / imported as background so plans can overlay photos / or hand coloured scribbles ~ you can get interesting results this way.

beegee
2004-07-06, 01:35 AM
Personally I like images combining a mix of realism with off the wall abstract ~ Plans as well as Images. Any image can be scanned / imported as background so plans can overlay photos / or hand coloured scribbles ~ you can get interesting results this way.Good point Roger,

If you, or anyone else have some examples of this technique, I'd love to see them posted in the Gallery.

Roger Evans
2004-07-06, 02:15 AM
Ok I've posted some test images for starters

Damo
2004-07-06, 10:54 AM
Peter,

The first crucial thing with photomontage is to record your actual position where you take the photograph of the existing building. Measure or triangulate your position, then position your Revit camera viewpoint in the exact same place. Saves hours of endless tweaking.

Maybe not the answer you are looking for, but we are experimenting with a more stylised form of imagery rather than going for the photoperfect realistic image. Sure it can be done, but we don’t have the time. Additionally, having a stylised image leaves a little flexibility at later design stages. We wouldn’t want to be too descriptive in case something needs to be changed at a later stage, this would allow 3rd parties to use it against us. “Hey, you showed the roof going to be X, and now it’s Y”. We might invest in Peranesi if Photoshop isn’t giving us the results. It’s all about time unfortunately. It’s either got to be 99% realistic, or obviously stylised.

Of course, other peoples views may differ (excuse the pun).

With regard to the night shot, I think a single light source is always too harsh. Most visualisations have multiple (invisible) light sources that gave a little background, or diffused, lighting that lifts the shadows.