VRay settings issue

[andymaw]

Hi all,

Hope you can help with a couple of questions, I really can't work out what's going on.

 

Trying to achieve a wireframe render of some buildings (very simple, they're just blocks that show the outline that I was sent in SketchUp format) to put into a photomontage.

 

I'm using a daylight system with VRay sun and all VRay cameras (set at the defaults) but I'm getting the result you can see attached. The material I'm using is the standard VRay material with the diffuse set to white then using the VRayEdgesTex to get the wireframe. The preview shows up perfectly with semi-transparent white diffuse colour and black lines but the render throws up weird triangles and parts of it are black.

 

 

I wondered whether it was to do with the sketchup model and the need to flip the normals on some faces, I did that but still no joy.

 

Just turned on Indirect GI (all defaults) and get more of a result but still strange triangles. Pic attached.

 

 

I'm a bit new to all of this so any help is greatly received. Using VRay 2 by the way.

Edited October 31, 2013 by andymaw

[Nicolai Bongard]

Not sure but it might be a smoothing group issue. Sometimes geometry imported from other programs are not all that great (allthough it might appear to be). Faces that should be 1 poly might be split up, and so can verteces. This sometimes looks horrible/gives unexpected results when you render. Try to convert your geometry to editable poly, then go to vertex mode, select all verteces and weld with a very small amount so that only verteces close to eachother (that ideally should be 1 vertex) get welded into 1. Then go to poly mode, select all faces and press autosmooth. Then try to render and see if it has been fixed.

[andymaw]

You were spot on with the triangles problem, thanks. Tried to weld but turned out the model was awful, components all over the place, doubled up vertices etc etc. so have remade the models. No more triangles and after a lot of playing and then an embarrassing moment where I realised there were at least 2 copies of the buildings underneath, it's all sorted.

 

Thanks for your help.

[andymaw]

Spoke too soon! I want the buildings to be semi transparent white with black wireframe but this is what I'm getting. Any thoughts?!

 

[Ismael]

There is nothing wrong with your results. The roof is white on account of it getting strong direct light on it. The rest is gray as it sits in the shade produced by your 50% opacity material. You may have to add lights in the interior to bring up its 'white'. Or you can use a double sided material with the inside material the same but with a different opacity so it turn more white or, no opacity alt all.

[andymaw]

I'm struggling to see how that can be right. When I change the opacity back up to 100% it renders the shadows as pitch black, which you surely wouldn't get from the sun. Could it be because the models are all in space? There are no planes because I need to be able to put the render into a photo.

 

Are there any other methods of getting to what I want to achieve? Perhaps just with GI? I just want the buildings to be white with black wireframes.

[andymaw]

Managed to set up the render using GI alone which is producing a better output.

 

Could anyone tell me why the wireframe lines are not crisp though? It's coming out looking a bit sketchy in style. On a tight deadline and starting to get that element of panic!

 

[Nicolai Bongard]

I would guess that is some antialiasing issue, or lack of. As in the lines are too thin and the geometry is slightly skewed, so there are some issues with drawing the lines "correctly". Try either larger black lines or a larger render output perhaps.