Speckling

brown.pauljames

I'm currently working on my first render. I'm having a problem with some speckling in the top left corner... a pattern of dots which you can see clearly in the second image. The first image I decided to put some more light on the subject but you can still see the speckling. Everywhere else is fine. Any pointers would be great

Thanks in advance

mjc1016

I can't really pick out anything in the size that they come in at...try posting 'full size' images (the file size in bytes seems to be more important than dimensions) and the forum software will resize/make a smaller image in the thread...

mark128

I cannot see the speckles in these images.

Are you using lights with the shadows set to deep shadow map? Deep Shadow Map lights have a known problem with producing defects that look like speckles. I always use ray traced shadows.

Miss B

I can't see any speckling either, just the texture of the column/wall on the right side of the render.

BTW, not a bad first render, not bad at all.

Tjeb

I've enlarged both pictures in Photoshop. Can't see anything unusual. I think it's just the texture.
In fact, if this was my scene, I would create a Bump map for the wall to give it a more interesting look.

brown.pauljames

mark128 said:

I cannot see the speckles in these images.

Are you using lights with the shadows set to deep shadow map? Deep Shadow Map lights have a known problem with producing defects that look like speckles. I always use ray traced shadows.

I think its Ray traced shadows, but I will double check. There are just a few light dots on the top left (sorry I said right originally my bad! apologies) in the black of the wall at the background rather than the near wall.

Thanks Miss B! :)

I've enlarged both pictures in Photoshop. Can't see anything unusual. I think it's just the texture.
In fact, if this was my scene, I would create a Bump map for the wall to give it a more interesting look.

I think you are right its the texture. How would I go about creating a Bump Map?

Tjeb

How would I go about creating a Bump Map?

Load your texture in your image editing software (Photoshop, Gimp, Paint Shop Pro) convert it to Black&White;,
add a little Gaussian blur (value depends on the resolution of the texture)
and save it with the original filename but add BUMP to it. (but that's up to you of course)
That is my way of doing it.

brown.pauljames

Thanks tjeb! I'll give that a go at the weekend

jestmart

That is a bad way to make a bump map, especially for that texture, the white mortar will end up looking raised.

Chohole

jestmart said:

That is a bad way to make a bump map, especially for that texture, the white mortar will end up looking raised.

I agree. If you want to make a bump map that way you will need to invert it, or use the bump settings as negative. (I don't know if you can do that in DS)

Tjeb

I don't bother to invert it. In case it turns out wrong, you change the negative values into positive or vice versa.
On the right half of the image where I used the Bump map as a Displacement map the effect on the mortar is more distinct.
I agree the rough look on the bricks is too much, but that's not the point now.