Jump to content
CinnamonMetal

Points intersect only on the Red and opening particle and surface normal points

Recommended Posts

The geometry has red and black color, the points coming in are particles; I only want the particles to intersect with the parts of the geometry which are red. The parameter is to control if I want some particles to bleed into the black areas of the geometry.  Although neither is working, the particles are intersecting with both the black and red parts of the geometry ?

As well, I want to open the point clouds based on the dot product of the particle normal and the surface normal, I'm assuming I should use the UVW of the intersect for the position and the primitive of the intersect as the maxpoints, which I can then control the radius of how many points I want to open ?

intersect.thumb.jpg.7abe197f85d2622c17e940c7db8e8856.jpg

 

Share this post


Link to post
Share on other sites

How do I get points to only effect the @Cd.r of the geometry; the current way is not working; the intersect is casting rays on the whole geometry regardless of the color on the geometry ?

Share this post


Link to post
Share on other sites

Use a compare node to check if the @Cd.r is greater than your threshold value, and then drive a switch with that so it should cast rays only on the red geo :

image.thumb.png.7be9b775078631c86ecf7381bebaddf1.png 

Share this post


Link to post
Share on other sites
1 hour ago, DonRomano said:

Use a compare node to check if the @Cd.r is greater than your threshold value, and then drive a switch with that so it should cast rays only on the red geo :

image.thumb.png.7be9b775078631c86ecf7381bebaddf1.png 

The points continue to project on the black as well as the red.

Share this post


Link to post
Share on other sites

What about sharing your file ? We'll be able to see what's not working and not wasting our breath here. It may come from another node..

 

Cheers, 

Share this post


Link to post
Share on other sites

I don't understand what you're trying to achieve, what's your goal here. Do you want just some particles to slide on the red geometry and some other to keep their way or is it something completely different ? 

Share this post


Link to post
Share on other sites

I want the particles to slide only on the parts of the geometry which are red, not the black areas, but using a parameter having some control whether some of the particles bleed into the semi-black areas is required. 

Share this post


Link to post
Share on other sites
Posted (edited)

you could delete the poits with Cd.r<0.001 first, then intersect and use Cd.r as Alpha or pscale value. If you want to keep the black points you can skip the intersect like romain showed.

Edited by nuki

Share this post


Link to post
Share on other sites

The point have no color on them, only the geometry, are you saying to transfer the Cd.r from the geometry to the points; the points still won't confine to the red areas of the geometry; as well as I want that bleed.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×