Hi there
I've been playing around with making a simple shader in houdini.
I get the look I want in the Render view, but when I render it out to disk using the same mantra node and referenced camera, I get very different results.
It's blank if I use any alpha properties and the texture is rotated 90 degrees.
I understand the Scene view being different but shouldn't the render view correlate?
Thanks
John

Hi John,

Do you have a hip file that you can post? One potential difference between the Render View and rendering to an image is that the Render View always uses the ray-tracer. I don't see why this would cause the difference that you're seeing though.

Thanks,
–Ian

Hi there Ian
that's brilliant, if you don't mind taking a look.
cheers
John

Hi John,

I had a look at your file and the problem is related to ray-tracing vs. micropolygon rendering. In particular, in micropolygon mode, the parametric surface coordinate “s” being fed into your Texture VOP is always 0, so your texture map lookups occur only along the edge of your texture. To get consistent results between the ray-tracer and micropolygon renderer, enable “Shade Curves as Surfaces” on your object (Render / Dicing tab).

Also, note that you can see the results of the micropolygon render in the Render Viewer when the Render Viewer's “Preview” toggle is off.

Hope that helps.

Kind regards,
–Ian

Hi Ian
that helps loads, I can carry on experimenting now
thanks a lot for the help
john

Thanks Ian that got it working fine.
Just a quick question
I've got the look I want on the contours of my extruded text objects.
I'd like to add a bit of randomness to the lines , at the moment the texture is wrapping the same image over each segment (primitive or vertices?).
I've done this with sprites before and made a point string attribute called baseColorMap and randomised the string text to select different stills in a folder.
like this
“$HOME/Desktop/alan/numbers/numb.a.`int(rand($PT)*5)`.jpeg”

I've tried this with a per primitive attribute but to no avail.

How would you recommend going about doing this?

Thanks again for the advice.

John

Hi John,

I would use a random primitive attribute as an offset. To the offset, add the frame number ($F) to get the image number. In other words, we want something like this: “MyPic_($F + offset).pic”. I threw together a quick example hip file based on your own. It's messy, but hopefully is along the lines of what you're after.

Hey Ian thanks for cooking that up.
I've got it working nicely and thanks for the introduction to the modulo and print nodes they're very handy indeed.
Thanks
John