Latest render glitch in city scene...

[ShaunDon]

Hey all.

Here's a section of a rendering I'm working on. I've never seen these kinds of white blotches with black outlines, hoping that they're indicative of something someone here can suggest.



1.46 has a great deal of awesome improvements over 1.09, but every job I've done with it over the past two months has been one headache after another with memory exception errors and render crashes. I haven't missed a deadline yet, but I've worked far too many 14-hour days and seven-day weeks in that time to deliver. I mean, I've been fixing this latest glitch on Easter Sunday for Christ's sake (pun intended!). This particular scene we have to render in stripes because the light cache crashes if one machine tries to calculate the whole image, and we're still getting these aggregious errors.

I've checked and rechecked -- there are absolutely no standard materials in the scene. The other standard advice I get is check for double meshes. This scene spans six full city blocks, and just checking the models we get back from our vendors for errors would be a full time position, so I'm sure there's a screwup or two at least. But here the site's really bad, and I modeled that.

Thanks guys.

Shaun

[vlado]

In the VRay messages window, you are probably getting warnings about overbright or invalid colors, with some references to objects in the scene.

You may want to check the materials of those objects.

This kind of dots can appear because:
(*) Some objects have missing UVW coordinates
(*) Some bitmaps do not have their "Apply crop" option ON.
(*) RPCs are known to cause problems like these sometimes.

The first thing you can check very quickly if you attempt to render the scene with the scanline renderer.

As for the light cache crashes, try to disable the light cache preview for your final rendering (Show calc. phase option -> OFF).

Best regards,
Vlado

[ShaunDon]

Thanks Vlado -- you're a peach.

[paulison]

hey so what caused it in the end? bet it was those RPC vehicles?

im curious about this project...we may be getting a city to model and render but I'm thinking using aerial photo's for the roads etc which looks like what you did as well. We are investigating using LIDAR which is a laser height measurement system that you put in a plane with GPS to plot out heaps of points for building heights as a quick way of modelling the bulk of the city. Anyone got any experience with this?

[ShaunDon]

I followed Vlado's advice and combed through the log. Serves me right for normally turning it off. He was right, I was getting zounds of overbright errors. I turned object sets off one by one, then went through all the buildings, and finally found the one that stopped the errors. We had a progress deadline yesterday, so I just left the building off and then comped a separate pass of it in -- I need to go back now and pull it apart to find what exactly was wrong with it, but it definitely wasn't the RPCs.

I also gotta say that the VRayProxy has totally made this project possible for us. We're developing nearly six city blocks for this aerial tower rendering, and max was crashing under the weight until I proxied out all the building models. Brought our 30-40 meg scene file down to 2.5, and it's been a breeze to work with.

I'm a little tired of the RPC cars, and while they weren't the problem this time, they often are -- considering our success with the VRayProxy, we just bought Dosch's Cars 2004 set and I'm prepping them with VRay mats and burning them to vrmesh files. There's 15 cars, about as many as we have RPCs, plus you can quite easily change the paint colors. Well worth what Dosch is asking for.

This particular model is a chunk of Providence, RI -- I don't know how dense your city project will be, but we pulled satellite photos off Terra Server and used reference photos compared shadow lengths to get building heights. The roads are 3D, but the satellite photography was great to trace geometry off of...

I don't post my finished work much as I'm usually too humbled by what's normally being posted here, but we finish this job in a couple weeks and I'll try to remember to post the finished rendering when we're cleared by our client.

Shaun

[alkis]

you might wanna try the cars from lowlpolygon3d first
we have been using them for quite a while with amazing results.
we have a scene with 2000 proxied cars and renders beautifully.
they also work quite well for relatively close up shots
if you want cars for aerial shots etc these are the ones to get
regards
alkis

[percydaman]

we use the lowpolygon3d cars as well. Have worked very well for us as well.

[ShaunDon]

Thanks guys -- I think we have some of those in our library... I wanna say I pulled that bus from the lowpoly section, but god only knows if it's from the same collection.

Not sure I'll take the time to swap out the RPCs in this shot -- it is an aerial, so they're only ever 50 pixels in length at the most. The Dosch hires models will go in for our ground-level renderings.

I'll definitely rethink those lowpoly ones though. The time to process RPCs before the render is maddening.

Shaun

[percydaman]

man I hate RPC preprocessing. I seriously do them in a separate pass always.

[ShaunDon]

Better to do them as a pass too since they suck at taking on the scene lighting... always gotta correct their levels in Photoshop. Don't ask me why I had them in this scene... I guess I was eager to see some life on my new streets.

Shaun

[dbuchhofer]

Vlado what can we do to help isolate these errors? I've got a scene that does something similar (Cascading overbright errors that start from 1 object). and theres been at least 1 other case on the forum..

What do you need to be able to pick out which mesh is causing it?