creating texture files procedurally (and backing to desk)

[catchyid]

Hi,

I don't have any experience about this topic, so my question could be a total dumb  

I have a 3d model (i.e. alembic) with uv. My goal is to paint in 3D some colors on the model mesh (the painting is done procedurally) then save a uv map containing the procedural painting (let's say as .png). The goal is to load and use this newly generated texture in another shading program. Is this possible and how?

Thanks,

[StepbyStepVFX]

Hi,

Have a look at the Bake Texture ROP https://www.sidefx.com/docs/houdini/nodes/out/baketexture.html

This could help as well :

Hope I understood correctly :-)

[konstantin magnus]

Hi Khaled,

you can transfer geometry shapes and attributes to pixel maps with VEX functions such as uvsample(), xyzdist(), primuv(), volumesample() and nearpoint() inside a VOP2COP Generator. 

I attached examples covering:

1. Transferring attributes
2. Blending image textures by attributes
3. Tracing points
4. Tracing closed 2D curves
5. Tracing open 3D curves
6. Tracing flattened meshes
7. Sampling volumes

Combining those should give you a good variety of procedural image painting options, either directly or for masking:

      

Another option esp. for baking ambient occlusion or even rendering perspective views would be raytracing with the intersect() function.

GEO_to_COPs.hipnc

Edited October 5, 2019 by konstantin magnus

[catchyid]

Thaaaaaaaaaaaanks guys, I will look at your files you sent me Once more, thaaanks a lot

[vinyvince]

On 04/10/2019 at 3:04 PM, konstantin magnus said:

Hi Khaled,

you can transfer geometry shapes and attributes to pixel maps with VEX functions such as uvsample(), xyzdist(), primuv(), volumesample() and nearpoint() inside a VOP2COP Generator. 

I attached examples covering:

1. Transferring attributes
2. Blending image textures by attributes
3. Tracing points
4. Tracing closed 2D curves
5. Tracing open 3D curves
6. Tracing flattened meshes
7. Sampling volumes

Combining those should give you a good variety of procedural image painting options, either directly or for masking:

      

Another option esp. for baking ambient occlusion or even rendering perspective views would be raytracing with the intersect() function.

GEO_to_COPs.hipnc

 

Edited September 11, 2020 by vinyvince

[konstantin magnus]

Hi Vincent,

you can use those maps as masks when texturing. They transfer geometry information and potentially all sorts of attributes.

[vinyvince]

r...

Edited September 13, 2020 by vinyvince

[konstantin magnus]

Yes, this is just a technical concept for getting all kinds of geometries and their attributes from GEO- to COP-context. You can potentially create very specific maps with this. But it's not necessarily meant to be fed directly to an artist.

[Librarian]

Thanx @konstantin magnus for files   Data (attributes  Heaven)

[vinyvince]

On 04/10/2019 at 3:04 PM, konstantin magnus said:

Hi Khaled,

you can transfer geometry shapes and attributes to pixel maps with VEX functions such as uvsample(), xyzdist(), primuv(), volumesample() and nearpoint() inside a VOP2COP Generator. 

I attached examples covering:

1. Transferring attributes
2. Blending image textures by attributes
3. Tracing points
4. Tracing closed 2D curves
5. Tracing open 3D curves
6. Tracing flattened meshes
7. Sampling volumes

Combining those should give you a good variety of procedural image painting options, either directly or for masking:

      

Another option esp. for baking ambient occlusion or even rendering perspective views would be raytracing with the intersect() function.

GEO_to_COPs.hipnc

 

The snippest to grab N attribute from the obj and do the dot product mask doesn't seem to behave like it should, Doesn't look like reading N but i don"t see any error in the following snippet, did i miss something?

Im under H19, py3:

-------------

 

string geo_mesh = 'op:/obj/geo_1_textures/OUT'; // geometry path
vector uv_tex = set(X, Y, 0.0); // texture space

// assign image textures to UV coordinates
vector tex_0 = colormap(tex_A, uv_tex);
vector tex_1 = colormap(tex_B, uv_tex);

vector N = uvsample(geo_mesh, 'N', 'uv', uv_tex); // transfer normal attributes from geo
float mask = clamp( dot(N, {0,1,0}), 0.0, 1.0); // create mask based on normals direction

mask= pow(mask,0.8);
vector tex_diff = lerp(tex_0, tex_1, mask); // blend textures dependent on mask

vector color = tex_diff; // assigns texture to color vector
assign(R, G, B, color); // color vector gets assigned to R, G and B color components

[konstantin magnus]

43 minutes ago, vinyvince said:

do the dot product mask doesn't seem to behave like it should

Hi Vincent,

it seems to work on my side. Did you fill the image paths?

[vinyvince]

Yes Konstantin.

It's just when i blur the normal or even add a noise to it, the mask doesn't seem to react.

Very basic but i can't get the proper mask in the the Cop snippet right...

Off course i can't get it in SOP, but i will rather like pixel than point

Edited April 23, 2022 by vinyvince

[vinyvince]

Here thats working to import N

 

Edited April 23, 2022 by vinyvince