[Bf-cycles] Any sample on creating basic materials from scratch?

[Mohamed Sakr]

here is how it is done:
Attribute *attr_UV = attributes.add(ATTR_STD_UV);
UVMapNode* uvmap = new UVMapNode();
uvmap->attribute = ustring("");

this is per corner not per face or per vertex.
here is how I modify them in custom attributes: (per vertex for example):
Attribute * attr_UV = attributes.add(ustring("your uv custom name"),
TypeDesc::TypeVector, ATTR_ELEMENT_VERTEX);
UVMapNode* uvmap = new UVMapNode();
uvmap->attribute = ustring(" your uv custom name ");

in that case you do it per vertex, so your iteration must be on (points)
not on (faces * 3)


On Wed, Feb 21, 2018 at 3:36 PM, Mohamed Sakr <3dsakr at gmail.com> wrote:

> sorry my previous reply is wrong, what you do is already correct for the
> iteration, got confused here.
>
>
> On Wed, Feb 21, 2018 at 3:18 PM, Mohamed Sakr <3dsakr at gmail.com> wrote:
>
>> for (int f = 0; f < facecount; f++)
>> {
>> for (int i = 0; i < 3; i++) //al faces are tris
>> {
>> attr_data_uv[uv*3 + i].x = 1.0;
>> attr_data_uv[uv*3 + i].y = float(f) / 20.0f;
>> attr_data_uv[uv*3 + i].z = 0.0;
>>
>> //correct
>> uv++;
>> }
>> uv++; // <<<<<wrong , should be inside the inner loop of i
>> }
>>
>> On Wed, Feb 21, 2018 at 1:12 PM, F Escobar <materialesescobar at hotmail.es>
>> wrote:
>>
>>> I didn't manage to make this working yet
>>>
>>> * UVs are per face corner by default, verify that you are doing that or
>>> switch to ATTR_ELEMENT_VERTEX.
>>> I'm creating it per face, probably in the future I'll move to ATTR_ELEMENT_VERTEX
>>> but it is easier to keep in the simplified method for now.
>>>
>>> * Adding some random value like 0.12345 to all UV coordinates to see if
>>> they are having an effect at all.
>>> Unfortunatly I had no luck with this.
>>>
>>> * Create just an UVMapNode and output that directly, to see if the UV
>>> coordinates are getting loaded.
>>> ccl::UVMapNode *uvnode = new ccl::UVMapNode();
>>> uvnode->attribute = ccl::ustring("UVMap");
>>> graph->add(uvnode);
>>> graph->connect(uvnode->output("UV"), bsdf->input("Color"));
>>>
>>> I tried that but it is always black (I assume that it means 0 0 ),
>>> notice that if I connect a texture to bsdf->input("Color") it is rendered
>>> in a plain color (uvs are wrong) but the color is given by the texture so
>>> the shader looks ok.
>>>
>>>
>>>
>>> The mesh was created like this:
>>>
>>> ccl::Attribute *attr_uv = mesh->attributes.add(ccl::ATTR_STD_UV,
>>> ccl::ustring("UVMap"));
>>> ccl::float3 *attr_data_uv = attr_uv->data_float3();
>>> for (int f = 0; f < facecount; f++)
>>> {
>>> for (int i = 0; i < 3; i++) //al faces are tris
>>> {
>>> attr_data_uv[uv*3 + i].x = 1.0;
>>> attr_data_uv[uv*3 + i].y = float(f) / 20.0f;
>>> attr_data_uv[uv*3 + i].z = 0.0;
>>> }
>>> uv++;
>>> }
>>>
>>> I'm not sure if I missed any step.
>>>
>>> Thank you in advance
>>> ------------------------------
>>> *De:* brechtvanlommel at gmail.com <brechtvanlommel at gmail.com> en nombre
>>> de Brecht Van Lommel <brechtvanlommel at pandora.be>
>>> *Enviado:* martes, 13 de febrero de 2018 15:05
>>> *Para:* F Escobar
>>> *Cc:* Discussion list to assist Cycles render engine developers
>>> *Asunto:* Re: [Bf-cycles] Any sample on creating basic materials from
>>> scratch?
>>>
>>> The checker texture will not use UV coordinates by default, you'd need
>>> to link in a UVMapNode node for that. For the image texture node it should
>>> work though.
>>>
>>> It's not clear to me what is wrong. A few things you could try:
>>> * UVs are per face corner by default, verify that you are doing that or
>>> switch to ATTR_ELEMENT_VERTEX.
>>> * Adding some random value like 0.12345 to all UV coordinates to see if
>>> they are having an effect at all.
>>> * Create just an UVMapNode and output that directly, to see if the UV
>>> coordinates are getting loaded.
>>>
>>>
>>> On Tue, Feb 13, 2018 at 2:25 PM, F Escobar <materialesescobar at hotmail.es
>>> > wrote:
>>>
>>> Thank you it worked like a charm!
>>>
>>> I'm driving nuts with other issue now
>>>
>>> I've created my UVs with
>>>
>>> ccl::Attribute *attr_uv = mesh->attributes.add(ccl::ATTR_STD_UV,
>>> ccl::ustring("UV"));
>>> ccl::float3 *attr_data_uv = attr_uv->data_float3();
>>>
>>> Filled attr_data_uv and so, but I cannot see the checker only one plain
>>> color, same issue if I use a ImageTextureNode even if I set Tex->projection
>>> = ccl::NodeImageProjection::NODE_IMAGE_PROJ_BOX;
>>>
>>> Any tip on this?
>>> ------------------------------
>>> *De:* Bf-cycles <bf-cycles-bounces at blender.org> en nombre de Brecht Van
>>> Lommel <brechtvanlommel at pandora.be>
>>> *Enviado:* jueves, 8 de febrero de 2018 15:34
>>> *Para:* Discussion list to assist Cycles render engine developers
>>> *Asunto:* Re: [Bf-cycles] Any sample on creating basic materials from
>>> scratch?
>>>
>>> Hi,
>>>
>>> We don't have any example code for this specifically. It's easiest to
>>> create node with the corresponding class directly.
>>>
>>> CheckerTextureNode *checker = new CheckerTextureNode();
>>> checker->color1 = make_float3(1.0f, 0.0f, 0.0f);
>>> checker->color2 = make_float3(0.0f, 0.0f, 1.0f);
>>> checker->scale = 1.0f;
>>> graph->add(checker);
>>> shader->set_graph(graph);
>>>
>>> If you want to use the generic API, don't create your own SocketType,
>>> look it up in the node.
>>>
>>> const SocketType *color1 = snode->find_input(ustring("color1"));
>>> snode->set(*color1, make_float3(1.0f, 0.0f, 0.0f));
>>>
>>> Regards,
>>> Brecht.
>>>
>>>
>>> On Thu, Feb 8, 2018 at 2:13 PM, F Escobar <materialesescobar at hotmail.es>
>>> wrote:
>>>
>>> I tried with this:
>>>
>>>
>>>
>>> ccl::Shader *shader = new ccl::Shader();
>>>
>>> if (scene != NULL)
>>> scene->shaders.push_back(shader);
>>>
>>> shader->name=ccl::ustring(material->mName);
>>> ccl::ShaderGraph *graph = new ccl::ShaderGraph();
>>>
>>> const ccl::NodeType *node_type = ccl::NodeType::find(ccl::ustri
>>> ng("checker_texture"));
>>> if (!node_type) {
>>> fprintf(stderr, "Unknown shader node \n");
>>> }
>>> else if (node_type->type != ccl::NodeType::SHADER) {
>>> fprintf(stderr, "Node type \"%s\" is not a shader node.\n",
>>> node_type->name.c_str());
>>> }
>>>
>>> ccl::ShaderNode* snode = (ccl::ShaderNode*)node_type->create(node_type);
>>>
>>> ccl::SocketType color1;
>>> color1.type = ccl::SocketType::COLOR;
>>> color1.name = ccl::ustring("color1");
>>> snode->set(color1, ccl::make_float3(1.0f, 0.0f, 0.0f));
>>>
>>> ccl::SocketType color2;
>>> color2.type = ccl::SocketType::COLOR;
>>> color2.name = ccl::ustring("color2");
>>> snode->set(color2, ccl::make_float3(0.0f, 0.0f, 1.0f));
>>>
>>> ccl::SocketType scale;
>>> scale.type = ccl::SocketType::FLOAT;
>>> scale.name = ccl::ustring("scale");
>>> snode->set(scale, 1.0f);
>>>
>>> graph->add(snode);
>>> shader->set_graph(graph);
>>>
>>>
>>> But I had crashes creating color2 probably I'm doing it wrongly, is
>>> there any sample on this?
>>>
>>>
>>> Thank you in advance.
>>>
>>> _______________________________________________
>>> Bf-cycles mailing list
>>> Bf-cycles at blender.org
>>> https://lists.blender.org/mailman/listinfo/bf-cycles
>>>
>>>
>>>
>>>
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>>>
>>>
>>
>
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