Ambient light incorrect.

[alfienoakes]

I am trying to render the attached house types in Viz 2006, with Vray free.

 

All is Ok apart from one reccurring problem. Every now and then, I get some rogue "dark" materials in the scene. They are always the ones that are in shadow, and all have proper materials added to them.

 

I have attached two renders to illustrate the problem. The materials are standard VIZ 2006 materials, with just a shade added in the diffude slot, locked with the ambient slot.

 

If anyone has any tips as to how to get rid of this, you will be my best friend for ever...!!

 

Regards

 

Andy

 

Viz 20006 and VRAy free..!

[Craig Ramsay]

Looks like it's double faces (one face on top of another) check your geometry and see if that's the problem

[alfienoakes]

Craig,

 

Thanks for posting, but its not that. All the objects are drawn in ADT 2005, and are single instances.

 

I have been back in and had a look at the originals all OK..

 

It does seem to be a problem between ADT and Viz.. but only shows up when I use Vray?? It has never done it with scanline..??

 

I have posted a question on an ADT forum, to see if anyone has any ideas..

 

Cheers

 

Andy

[Craig Ramsay]

Have you actually checked in viz that theres no overlaping faces?

[steven martin]

I had a similar problem with vray free when I was experimenting and came to the conclusion that it was a problem with vray free.

 

Sometime it would do it and sometimes it wouldnt. Save your scene, restart your pc and try the render again.

 

You may find it has magically disappeared

[alfienoakes]

Craig..

 

They are ADT objects, so when I bring them into VIZ, they are just that, ADT objects. In Viz they show up as separate components, so I can highlight them, and see what is what in the drawing.

 

As far as I am aware, there are no extra faces.. unless when it comes into VIZ it does somehow create an extra face..

 

Is this possible..?

 

Steve..

 

Did the problem you experience, seem to be if you copied an object in ADT and placed it in the scene somewhere?? It appears that this is when the error happens..

 

For instance, I created a fascia board out of a mass element, and copied it to another portion of the roof. When I imported it into VIZ, the original mass element rendered fine, yet the copied one would not render correctly.

 

So I had to go back in to ADT, delete the copied fascia, and creat e a new one from scratch.. Then it worked OK.

 

Thing is, I' am now not sure if this is a problem with VRAY free,, VIZ, or ADT!!!

 

Andy

[Tim Saunders]

now wait a minute... the second image is okay right? it looks like you are talking about the black window frame right? a year ago i had an adt class. we had to design a building using adt. i had a concurrent class where we had to design an actual project for an actual client. i was able to make the same project work for both classes. to sell the design to the client i was in charge of the rendering of the design. after importing the dwg file, i noticed there were several elements that adt puts in the model that is really un-needed for a 3d presentation. this is of coarse to maintain the models "BIM-ness". hope you know what i mean. it actually did place extra geometry that made things render wierd with scanline. i ended up haeing to trace the object in viz to re-model it. that is where my hatred for ADT began. just re-model the frames, i mean they're just frames.

[alfienoakes]

Hey Tim,

 

You know what... I think you are probably right. Its just a nightmare.

 

I have posted a question on the ADT forum at Autodesk, but no one has come back with an answer yet.

 

To make matters even worse, I finally managed to get all of my windows etc into each model; I have two house types. They all worked in their respective drawings.. no dark frames etc.

 

So I xref'd them into my site plan in VIZ, thinking all the hard work had been done.... and guess what.

 

MORE DARK FRAMES!!!! I am losing patience very quickly here. I love ADT as we can chuck out a building in super fast time.. but this is really testing me at the mo..

 

I have attached an image of the site, to show what it does on the site plan now. Look at the first floor frames. They are exactly the same materials and in some instances, the same windows as the ones that are on the other houses first floors.

 

Cheers

 

Andy

[alfienoakes]

OK...

 

For the benefit of anyone else who has this problem.. here is what I think it is.!

 

Its actually an ADT problem, but we've been in the VRAY section for so long now, and hopefully this should lick it.

 

In ADT, it creates the frame, and assigns the glass, mullion, stops etc as separate entities. They are all one "object" though in ADT.

 

When you bring them into VIZ, they become separate entities, each with a name that applies to the group of those entities, ie, all similar mullions, walls, doors etc.. So when you apply a material to one of them, all the other like objects take that material as well.

 

But, what VIZ also does, is creates a "controling" extra object..(well thats what it seems like)

 

If you look at the first image, you can see the render with the problematic faces.

 

The second image is all the other objects turned off, but window related objects on. The third image, is with all the normal window objects selected, and hidden, but the controlling layer left. See there is nothing there when rendered.

 

But the forth image, is the same image, but in VIZ with the invisible layers selected. You can see that there is something there.

 

The fifth image is with this "invisible" layer removed, and the windows turned back on.

 

I am still looking into it, but hope that this is what the problem is.

 

Craig.. you were indeed correct, it is overlapping faces, but they are not visible, they only seem to cause a problem, when everthing is on together. If you try and render just the problem faces, you see nothing..!!

 

I hope that clears it up, and thanks for all your comments..!

 

Next stop WIP posts for some proper work, not just trouble shooting!!

 

Regards

 

Andy