Hi everyone,

Yesterday I rendered a car I made some time ago.
The rendered image looks fine except for the license plate.
There are some strange spots on it, I can't explain.
The shader for the license plate has a single color, 75% highlight, 17% shininess and 16% reflection.
Does anyone why there are these strange spots on it, and how I can get rid of them ?

Thanks in advance.

I think they would be gone without reflection. Couldn't it be something that is on the hdri file? Or the texture on the (probably infinite) plane the car is on? It could not be a shadow issue (that should be visibile elsewhere) Besides that, a inverted black and white version of the texture in the bumpchannel would help in avoiding the slightly flat look. Groeten uit Soesterberg!

I don't think it has got anything to do with the HDRI file, because I get the same results when I use one of those dreamscape backgrounds. But I'll put the reflection to zero, see what happens.

What do you mean with your last sentence (flat look)?

Alvast bedankt

Attached Link: http://www.eovia.com/download/updates_car.jsp

With a something in the bump channel the black letters could get the typical raised (embossed) look they have in reality (with a little highlights on the edge). On the, eh, nummerplaat, I meant. Try unchecking 'interpolation', maybe the light does something strange in that particular part of the model. Because it is a kind of plane, while the rest of the car (very nice looking car that is) is all curved that could be the only place the interpolation plays it's ugly part. Did you download the update by the way? It takes care of some of that artefacts. Prettig weekend!

From what I have read on previous posts, uncheck interpolate like Hoof said and increase the lighting quality setting.

Yes I installed the 3.0.1 patch. I did some testing, and indeed the interpolation was causing the problem. If I put the reflection to zero the spots are also gone even with interpolation on. Thanks for all the input, Enjoy the weekend.

Hey! Don't leave us hanging! Looks cool and I'd love to see how it came out. Nice stuff. I've never had the guts to build a car yet. They always look scary to model and to texture. I think yours is great. -Kix

agreed... I like this car... is it a real one?... looks to me like the illegitimate offspring of a Ferrari and a Porsche. very nice work so far... definitely could use a bump map on that license plate.

It's a slightly modified version of a Porsche 996 GT2.

A bump map on the license plate sounds like a good idea, but how do I do that ?

Another picture :o)

Porsche looks very nice. Use a desaturated, inverted jpeg of the letters as the bump map.

Some (Gaussian) blur in your pixelpusher app of choice will get a smooth transition from high to low. You can use the same idea to raise the Porscho logotyp on the front of the car. Bumpmapping is VERY nice in getting additional detail, without modelling it. You could use it to breathe some life in the lights/the plastic that covers them (It does not have to be a texturemap in all cases, even with procedural shaders, you could use 'wires' or 'scan lines' for the lights on this car).

But every part of the car (the logo, the license-plate, the letters GT4) are modelled, there are no textures (only the infinite ground-plane)

Well, that is something else... And they're, like, ultrathin flat things, you can actually move around? Or are these just shading domains? Adding depth or bevels then would be a bit more difficult then... If you want depth, then, you would actually have to make it. Or remake it, in this case. Replacing the 22-XP-JV stuff with a Text object for instance. Did you model it yourself or did you buy or find it somewhere? Because I think there is a big chance you have to leave it here, to keep things simple. And to keep yourself from getting bored with this car.

Indeed they're all ultrathin surfaces. I modelled everything myself. the logo and GT4 I drew in MicroStation (A kind of AutoCAD), with pictures from the internet as refrence. The license-plate I also drew in Microstation. I took all the dimensions from the license-plate of my own car (including all the nummbers, stars, letters etc..) Nevertheless, I'll keep in mind everything what is said about bumpmapping, who knows when it comes in handy.

Increasing the Sky Light may lighten or remove those ashy areas. -Shonner

I just cured a problem I was having with ash by enabling caustics.